Want to learn to build Android apps in Kotlin? Get started with the Kotlin Bootcamp for Programmers and Developing Android apps in Kotlin codelabs courses.
Google and Udacity currently offer video-based courses for Kotlin Bootcamp and How to build Android apps in Kotlin. To help people that learn in different ways, we have recently reworked these courses to publish them as tutorial-based codelab courses. More than 2.5 million users have worked through Google codelabs like this just this year.
Google provides first class support for building Android apps in Kotlin, including Kotlin-friendly Android APIs and API extensions. Kotlin fully interoperates with the Java programming language and libraries, and is included with IntelliJ and Android Studio.
In the Kotlin Bootcamp course, you will learn everything you need to program in Kotlin, beginning with the basics such as how to write Kotlin statements, and working up to functional manipulation such as extending builtin functions.
If you already know how to program, the Kotlin Bootcamp provides the foundation you'll need to build Android apps in Kotlin.
Start the Kotlin Bootcamp now!
When you feel comfortable with Kotlin, you can dive right into building Android apps. This course takes you from "Hello World" to connecting with the world. You start building a basic interactive user interface on one screen, and end with a multi-screen Google Developer Group (GDG) Finder app that gets data from a live server on the internet. In between, you learn about Android Jetpack components, such as Room for databases, Work Manager for background processing, the Navigation component, and more. You'll use popular community libraries to simplify common tasks, such as Glide for image loading, Retrofit for networking, and Moshi for JSON parsing. The course teaches key Kotlin features such as coroutines to help you write your app code more quickly and concisely.
In each lesson, you will work with a realistically architected app and implement key features. For example, you start out learning how to deploy a dice roller app. You learn how to implement navigation by building the "Android Trivia" game. You learn how to create a Room database by building a sleep tracker app.
Overall, you will create and work with more than 10 apps, so, by the end of this course, you will have a portfolio of example code that you can use to realize your own amazing app ideas!
Get started now!
Billions of people rely on their Android-powered devices to securely store their sensitive information. A vital component of the Android security stack is the key attestation system. Android devices since Android 7.0 are able to generate an attestation certificate that attests to the security properties of the device’s hardware and software. OEMs producing devices with Android 8.0 or higher must install a batch attestation key provided by Google on each device at the time of manufacturing.
These keys might need to be revoked for a number of reasons including accidental disclosure, mishandling, or suspected extraction by an attacker. When this occurs, the affected keys must be immediately revoked to protect users. The security of any Public-Key Infrastructure system depends on the robustness of the key revocation process.
All of the attestation keys issued so far include an extension that embeds a certificate revocation list (CRL) URL in the certificate. We found that the CRL (and online certificate status protocol) system was not flexible enough for our needs. So we set out to replace the revocation system for Android attestation keys with something that is flexible and simple to maintain and use.
Our solution is a single TLS-secured URL (https://android.googleapis.com/attestation/status) that returns a list containing all revoked Android attestation keys. This list is encoded in JSON and follows a strict format defined by JSON schema. Only keys that have non-valid status appear in the list, so it is not an exhaustive list of all issued keys.
This system allows us to express more nuance about the status of a key and the reason for the status. A key can have a status of REVOKED or SUSPENDED, where revoked is permanent and suspended is temporary. The reason for the status is described as either KEY_COMPROMISE, CA_COMPROMISE, SUPERSEDED, or SOFTWARE_FLAW. A complete, up-to-date list of statuses and reasons can be found in the developer documentation.
REVOKED
SUSPENDED
KEY_COMPROMISE
CA_COMPROMISE
SUPERSEDED
SOFTWARE_FLAW.
The CRL URLs embedded in existing batch certificates will continue to operate. Going forward, attestation batch certificates will no longer contain a CRL extension. The status of these legacy certificates will also be included in the attestation status list, so developers can safely switch to using the attestation status list for both current and legacy certificates. An example of how to correctly verify Android attestation keys is included in the Key Attestation sample.
Posted by Sameer Samat, Vice President, Platforms & Ecosystems
From day one, we designed Android to be a flexible, adaptive platform.
Most people picture a smartphone when they think of Android, but Android also powers an amazing number of large-screen devices. In fact, there are more than 175 million Android tablets with the Google Play store,1 making Android tablets a vital form factor for Google and our OEM partners today. Android apps also run on Chrome OS laptops, and the number of monthly active users who enabled Android apps grew 250% in just the last year.2
Here at Google, we’re excited to see how you can take advantage of large-screen formats - including Samsung’s new Galaxy Tab S6, the upcoming Lenovo™ Smart Tab M8 with Google Assistant, the upcoming Samsung Galaxy Fold, and other devices launching this week at IFA. Our OEM partners are building experiences that help users every day:
From the start, Android was designed as a platform that could handle multiple screen sizes. Over the years, we’ve continued to add functionality for developers to accommodate new devices and form factors.
Android’s layout system helps applications smoothly resize and adjust their layout interactively.
By optimizing your app to take advantage of different form factors, developers have an opportunity to deliver richer, more engaging experiences to millions of users on larger screens. And if you don’t have access to physical devices, the Android Emulator supports all of the form factors mentioned above, from Chrome OS to phones and tablets.
Developers of apps like Mint, Evernote, and Asphalt are just a few who have seen success from taking their existing APK to larger screens.
To learn more about optimizing your Android apps for richer experiences on tablets, Chrome OS laptops, foldables, and more, join us at the Android Developer Summit on October 23-24 — either in person or via the livestream — or check out our recap videos on YouTube.
Sources:
[1] The number of tablets only accounts for devices that have the Google Play Store installed (for example, this excludes tablets in China); the actual number of tablets capable of running Android applications is much larger.
[2] Google Internal Data, March 2018 to March 2019.
Posted by Stephanie Cuthbertson, Senior Director of Product Management, Android
After more than a year of development and months of testing by early adopters, we’re ready to introduce Android 10 to the world!
Android 10 is built around three important themes. First, Android 10 is shaping the leading edge of mobile innovation with advanced machine-learning and support for emerging devices like foldables and 5G enabled phones. Next, Android 10 has a central focus on privacy and security, with almost 50 features that give users greater protection, transparency, and control. Finally, Android 10 expands users' digital wellbeing controls so individuals and families can find a better balance with technology.
Today we're releasing the Android 10 source code to Android Open Source Project (AOSP) and making it available to the broader ecosystem. We’re also starting the official Android 10 rollout to all three generations of Pixel devices worldwide. Many partner devices, including those in the Beta program, will receive the update by the end of the year.
Thank you for your support during this year’s Beta -- more than 200,000 of you tested early releases on 26 different Beta devices, reporting 20,000 unique issues. That’s on top of the many articles, discussions, surveys, and in-person meetings where you voiced your thoughts, and the work you did to make your apps compatible by today’s release. Your support and engagement are what make Android such an amazing platform. Together with our OEM partners you’ve created more excitement for this Android release than we’ve ever had. In fact, Android 10 will be available on more devices than any other previous release. Android is fortunate to have such a passionate community!
To get started developing for Android 10, visit developer.android.com/10.
Here’s a look at what’s in Android 10 and how you can use it today. Make sure to check out our Keyword blog for more too!
With Android 10 you can take advantage of the latest hardware and software innovations to build amazing app experiences for users.
Foldables - Building on robust multi-window support, Android 10 extends multitasking across app windows and provides screen continuity to maintain your app state as the device folds or unfolds. For details on how to optimize your apps for foldables, see the developer guide.
5G networks promise to deliver consistently faster speeds and lower latency, and Android 10 adds platform support for 5G and extends existing APIs to help you take advantage of these enhancements. You can use connectivity APIs to detect if the device has a high bandwidth connection and check whether the connection is metered. With these, your apps and games can tailor rich, immersive experiences to users over 5G.
Live Caption automatically captions media playing on users’ devices, from videos to podcasts and audio messages, across any app. The ML speech models run right on the phone, and no audio stream ever leaves the device. For developers, Live Caption is optional, but expands the audience for your apps and games by making your content more accessible with a single tap. Live Caption is coming to Pixel devices this fall, and we’re working closely with our partners to launch it broadly on devices running Android 10.
Smart Reply in notifications - Android 10 uses on-device ML to suggest contextual actions in notifications, such as smart replies for messages or opening a map for an address in the notification. We’ve built this feature with user privacy in mind, keeping the ML processing completely on the device. Your apps can take advantage of this feature right away, or you can opt-out if you’d rather generate your own suggestions.
Smart Reply can suggest actions based on notification content.
Dark theme - Android 10 adds a system-wide dark theme that’s ideal for low light and helps save battery. You can build a custom dark theme for your app or let the system create one dynamically from your current theme. See the developer guide for details.
Dark theme in Google Keep
Gesture navigation - Android 10 introduces a fully gesture navigation mode that eliminates the navigation bar area and allows apps to use the full screen to deliver richer, more immersive experiences. Get started optimizing your app today.
Gesture navigation gives apps the full screen for content
Privacy is a central focus in Android 10, from stronger protections in the platform to new features designed with privacy in mind. Building on previous releases, Android 10 includes extensive changes to protect privacy and give users control, with improved system UI, stricter permissions, and restrictions on what data apps can use. See the Android 10 developer site for details on how to support these in your apps.
Giving users more control over location data - Users have more control over their location data through a new permission option -- they can now allow an app to access location only while the app is actually in use (running in the foreground). For most apps this provides a sufficient level of access, while for users it’s a big improvement in transparency and control. To learn more about location changes, see the developer guide or our blog post.
Protecting location data in network scans - Most of the APIs for scanning networks already required the coarse location permission. Android 10 increases the protection around those APIs by requiring the fine location permission instead.
Preventing device tracking - Apps can no longer access non-resettable device identifiers that could be used for tracking, including device IMEI, serial number, and similar identifiers. The device's MAC address is also randomized when connected to Wi-Fi networks by default. Read the best practices to help you choose the right identifiers for your use case, and see the details here.
Securing user data in external storage - Android 10 introduces a number of changes to give users more control over files in external storage and the app data within them. Apps can store their own files in their private sandboxes, but must use MediaStore to access shared media files and use the system file picker to access shared files in the new Downloads collection. Learn more here.
Blocking unwanted interruptions - Android 10 prevents app launches from the background that unexpectedly jump into the foreground and take over focus from another app. Learn more here.
On Android we’re always working to assess our ongoing security investments; we refer to this as measurable security. One way we measure our ongoing investments is through third party analyst research such as Gartner’s May 2019 Mobile OSs and Device Security: A Comparison of Platforms report (subscription required) which scored Android the highest possible rating in 26 out of 30 categories, ahead on multiple points from authentication to network security and malware protection. Read more about our long-term work on Security in Quantifying Measurable Security. But there is no finish line when it comes to Security. In Android 10, we’ve introduced even more features to keep users secure through advances in encryption, platform hardening, and authentication.
Storage encryption - All compatible devices launching with Android 10 are required to encrypt user data, and to make this more efficient, Android 10 includes Adiantum, our new encryption mode.
TLS 1.3 by default - Android 10 also enables TLS 1.3 by default, a major revision to the TLS standard with performance benefits and enhanced security.
Platform hardening - Android 10 also includes hardening for several security-critical areas of the platform, and updates to the BiometricPrompt framework with robust support for face and fingerprint in both implicit and explicit authentication. Read more about Android 10 security updates here.
Dynamic depth for photos - Apps can now request a Dynamic Depth image, which consists of a JPEG, XMP metadata related to depth related elements, and a depth and confidence map embedded in the same file. These let you offer specialized blurs and bokeh options in your app. Dynamic Depth is an open format for the ecosystem and we're working with our partners to bring it to devices running Android 10 and later.
With Dynamic Depth image you can offer specialized blurs and bokeh options in your app
Audio playback capture - Now any app that plays audio can let other apps capture its audio stream using a new audio playback capture API. In addition to enabling captioning and subtitles, the API lets you support popular use-cases like live-streaming games. We’ve built this new capability with privacy and copyright protection in mind, so the ability for an app to capture another app's audio is constrained. Read more in our blog post.
New audio and video codecs - Android 10 adds support for the open source video codec AV1, which allows media providers to stream high quality video content to Android devices using less bandwidth. In addition, Android 10 supports audio encoding using Opus - an open, royalty-free codec optimized for speech and music streaming, and HDR10+ for high dynamic range video on devices that support it.
Native MIDI API - For apps that perform their audio processing in C++, Android 10 introduces a native MIDI API to communicate with MIDI devices through the NDK. This API allows MIDI data to be retrieved inside an audio callback using a non-blocking read, enabling low latency processing of MIDI messages. Give it a try with the sample app and source code here.
Vulkan everywhere - Vulkan 1.1 is now a requirement on all 64-bit devices running Android 10 and higher, and a recommendation for all 32-bit devices. We already see significant momentum on Vulkan support in the ecosystem - among devices running Android N or above, over half support Vulkan 1.0.3 or better. With the new requirement in Android 10, we expect to see adoption rise even further in the coming year.
Improved peer-to-peer and internet connectivity - We’ve refactored the Wi-Fi stack to improve privacy and performance, and also to improve common use-cases like managing IoT devices and suggesting internet connections -- without requiring the location permission. The network connection APIs make it easier to manage IoT devices over local Wi-Fi, for peer-to-peer functions like configuring, downloading, or printing. The network suggestion APIs let apps surface preferred Wi-Fi networks to the user for internet connectivity.
Wi-Fi performance modes - Apps can now request adaptive Wi-Fi by enabling high performance and low latency modes. These can be a great benefit where low latency is important to the user experience, such as real-time gaming, active voice calls, and similar use-cases. The platform works with the device firmware to meet the requirement with the lowest power consumption.
ART optimizations - Improvements in the ART runtime help your apps start faster, consume less memory, and run smoother -- without requiring any work from you. ART profiles delivered by Google Play let ART pre-compile parts of your app even before it's run. At runtime, Generational Garbage Collection makes garbage collection more efficient in terms of time and CPU, reduces jank, and helps apps run better on lower-end devices.
This chart shows the percentage improvement in startup time for specific apps when tested using Play profiles.
Neural Networks API 1.2 - We’ve added 60 new operations including ARGMAX, ARGMIN, quantized LSTM, alongside a range of performance optimizations. This lays the foundation for accelerating a much greater range of models -- such as those for object detection and image segmentation. We’re working with hardware vendors and popular machine learning frameworks such as TensorFlow to optimize and roll out support for NNAPI 1.2.
With Android 10 we’re continuing our focus on bringing the new platform to devices more rapidly, working closely with our device-makers and silicon partners like Qualcomm. Project Treble has played a key role, helping us bring 18 partner devices into this year’s Beta program along with 8 Pixel devices -- more than double the number from last year. Even better, we expect those devices to get the official Android 10 update by the end of this year, and we’re working with several partners on other new flagship launches and updates. We’re seeing great momentum with Android 10 already, and more devices than any other previous Android release will be getting this new version in the months ahead.
Android 10 is also the first release to support Project Mainline (officially called Google Play system updates), our new technology for securing Android users and keeping their devices fresh with important code changes - direct from Google Play. With Google Play system updates, we’re able to update specific internal components across all devices running Android 10 and higher, without requiring a full system update from the device manufacturer. We’re expecting to bring the first updates to consumer devices over the next several months.
For developers, we expect these updates in Android 10 to help drive consistency of platform implementation broadly across devices, and over time bring greater uniformity that will reduce your development and testing costs.
Now with today’s public release of Android 10 and updates coming soon to devices, we’re asking all Android developers to update your current apps for compatibility as soon as possible to give your users a smooth transition to Android 10.
Here’s how to do it:
Getting apps tested and ready for the new version of Android is crucial to faster platform updates throughout the ecosystem, so please prioritize this work if possible.
Next, when you're ready, dive into Android 10 and learn about the new features and APIs that you can use. Here are some of the top features to get started with.
We recommend these for every app:
We recommend these if relevant for your app:
To read about all of the new features and changes, visit the Android 10 developer site.
To get started developing, download the official API 29 SDK and tools into Android Studio 3.5 or higher. Then follow these instructions to configure your environment.
Android 10 will begin rolling out today to the three generations of Pixel phones -- Pixel 3 (and 3a), Pixel 2, and even the original Pixel! All Pixel devices will get the update over the next week, including those enrolled in this year’s Beta program. If you own a Pixel device, watch for your official over-the-air update coming soon!
As always, the system images for Pixel devices are available here for manual download and flash, and you can get the latest Android Emulator system images via the SDK Manager in Android Studio. For broader testing on other Treble-compliant devices, Generic System Images (GSI) are available here.
If you're looking for the Android 10 source, you'll find it here in the Android Open Source Project repository under the Android 10 branches.
We'll soon be closing the Android Beta issue tracker and Feedback app, but please keep the feedback coming! You can file a new issue against Android 10 in the AOSP issue tracker.
Thanks again to the many developers and early adopters who participated in the Android Beta program this year! You gave us great feedback, and filed thousands of issues that helped us to make the Android 10 platform great for consumers and developers.
We're looking forward to seeing your apps on Android 10!
In May, we launched new Families policies to provide additional protections for children and families on Google Play. As part of this policy change, we’re requiring all developers to provide information on their app’s target audience and content via the Google Play Console by September 1st. Thanks to everyone who has completed it already. If you haven’t done so, please fill it out as soon as possible and consult our developer guide and training course for additional information.
Apps that include children in their target audience need to adhere to our new policy requirements including appropriate content, showing suitable ads (learn more), and disclosing personally identifiable information correctly. We’ve found that checking for these requirements takes longer than the normal review process, and can result in review times of up to 7 days (or longer in certain exceptional circumstances). Apps who submit inaccurate responses in the target audience and content section will also be subject to these reviews. You can find more details on Google Play’s app submission process in this Help Center article.
We respect that you are running a business and longer review times can impact how you work. Our goal is to prepare you for this change and minimize disruptions for you. These apps will be subject to extended reviews for every update, and you may need to update your processes to accommodate for additional review time. Suggestions for how to best adapt to this change include submitting your app at least a week before any important launch dates and (unless urgent) avoid resubmitting your app while it is under review.
These changes help make the Play Store safer through deeper and longer reviews, which is a tradeoff we think everyone is willing to make. Thanks for your continued support in building a positive and safe experience for all users on Google Play.
How useful did you find this blog post?
★ ★ ★ ★ ★
Posted by Adam Bacchus, Sebastian Porst, and Patrick Mutchler — Android Security & Privacy
We’re constantly looking for ways to further improve the security and privacy of our products, and the ecosystems they support. At Google, we understand the strength of open platforms and ecosystems, and that the best ideas don’t always come from within. It is for this reason that we offer a broad range of vulnerability reward programs, encouraging the community to help us improve security for everyone. Today, we’re expanding on those efforts with some big changes to Google Play Security Reward Program (GPSRP), as well as the launch of the new Developer Data Protection Reward Program (DDPRP).
We are increasing the scope of GPSRP to include all apps in Google Play with 100 million or more installs. These apps are now eligible for rewards, even if the app developers don’t have their own vulnerability disclosure or bug bounty program. In these scenarios, Google helps responsibly disclose identified vulnerabilities to the affected app developer. This opens the door for security researchers to help hundreds of organizations identify and fix vulnerabilities in their apps. If the developers already have their own programs, researchers can collect rewards directly from them on top of the rewards from Google. We encourage app developers to start their own vulnerability disclosure or bug bounty program to work directly with the security researcher community.
Vulnerability data from GPSRP helps Google create automated checks that scan all apps available in Google Play for similar vulnerabilities. Affected app developers are notified through the Play Console as part of the App Security Improvement (ASI) program, which provides information on the vulnerability and how to fix it. Over its lifetime, ASI has helped more than 300,000 developers fix more than 1,000,000 apps on Google Play. In 2018 alone, the program helped over 30,000 developers fix over 75,000 apps. The downstream effect means that those 75,000 vulnerable apps are not distributed to users until the issue is fixed.
To date, GPSRP has paid out over $265,000 in bounties. Recent scope and reward increases have resulted in $75,500 in rewards across July & August alone. With these changes, we anticipate even further engagement from the security research community to bolster the success of the program.
Today, we are also launching the Developer Data Protection Reward Program. DDPRP is a bounty program, in collaboration with HackerOne, meant to identify and mitigate data abuse issues in Android apps, OAuth projects, and Chrome extensions. It recognizes the contributions of individuals who help report apps that are violating Google Play, Google API, or Google Chrome Web Store Extensions program policies.
The program aims to reward anyone who can provide verifiably and unambiguous evidence of data abuse, in a similar model as Google’s other vulnerability reward programs. In particular, the program aims to identify situations where user data is being used or sold unexpectedly, or repurposed in an illegitimate way without user consent. If data abuse is identified related to an app or Chrome extension, that app or extension will accordingly be removed from Google Play or Google Chrome Web Store. In the case of an app developer abusing access to Gmail restricted scopes, their API access will be removed. While no reward table or maximum reward is listed at this time, depending on impact, a single report could net as large as a $50,000 bounty.
As 2019 continues, we look forward to seeing what researchers find next. Thank you to the entire community for contributing to keeping our platforms and ecosystems safe. Happy bug hunting!
Boris Valusek, Design Lead, Google Play
The Google Play Store has over two billion monthly active users coming to find the right app, game, and other digital content. To improve the overall store experience, we’re excited to roll out a complete visual redesign. Aligning with Material design language, we’re introducing several user-facing updates to deliver a cleaner, more premium store that improves app discovery and accessibility for our diverse set of users.
To make browsing faster and easier, we’ve introduced a new navigation bar at the bottom of the Play Store on mobile devices and a new left navigation on tablets and Chrome OS. There are now two distinct destinations for games and apps, which helps us better serve users the right kind of content. Once users find the right app or game, the updated store listing page layout surfaces richer app information at the top of each page as well as a more prominent call-to-action button. This makes it easier for users to see the important details and make a decision to install your app. You’ll also notice our new icon system with a uniform shape, helping content to stand out more over UI. If you haven’t done so already, make sure to update your icon following the new icon specifications as soon as possible.
If you’re looking for best practices to make a compelling store listing page, we have several resources to help. To ensure your page resonates well with Android users, use store listing experiments to test for the best app icon, images, video, and descriptions on Google Play. You can also tailor your marketing messages to specific user groups based on their country, install state or even pre-registration by creating custom store listings. For even more, try our free e-learning resource, Academy for App Success.
How useful did you find this blogpost?
Platform
Android Studio
Google Play
Android Jetpack
Docs
News
