08 December 2016

How augmented reality helps you buy furniture and capture Pokémon

Posted by Jamil Moledina, Games Strategic Lead, Google Play

Online furniture seller Wayfair and Niantic's Pokémon GO have more in common than you might think. Both of these companies use augmented reality to create innovative, immersive experiences for their users. I sat down with Mike Festa, Director of Wayfair Next, and Tatsuo Nomura, Product Manager for Pokémon GO, at our recent Playtime event to discuss how developers can make the most of AR as a platform.

From 3D furniture modelling in WayfairView using Tango, to logging countless miles catching Pokémon, hear how these developers are innovating with AR, and get their advice for others looking to use AR in their apps and games.

Check out more sessions from our global Playtime events to learn best practices for your app and game businesses. Also, stay up to date with more videos from events, product news, and tips to help grow your business on Google Play with the Playbook for Developers app.

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07 December 2016

Watch sessions from the Playtime 2016 events to learn how to succeed on Android & Google Play

Posted by Patricia Correa, Head of Developer Marketing, Google Play

We’re wrapping up our annual global Playtime series of events with a last stop in Tokyo, Japan. This year Google Play hosted events in 10 cities: London, Paris, Berlin, Hong Kong, Singapore, Gurgaon, San Francisco, Sao Paulo, Seoul and Tokyo. We met with app and game developers from around the world to discuss how to build successful businesses on Google Play, share experiences, give feedback, collaborate, and get inspired. You can now watch some of the best Playtime sessions on our Android Developers YouTube Channel, as listed below. The playlist opens with a video that celebrates collaboration.

Keynote

What’s next for Google Play

Learn how we're helping users discover apps in the right context, creating new ways to engage with users beyond the install, and powering innovative experiences on emerging platforms like virtual reality, wearables, and auto.

Develop and launch apps & games

Android development in 2016

Android development is more powerful and efficient than ever before. Android Studio brings you speed, smarts, and support for Android Nougat. The broad range of cross-platform tools on Firecase can improve your app on Android and beyond. Material Design and Vulkan continue to improve the user experience and increase engagement.

Daydream & Tango

Daydream View is a VR headset and controller by Google that lets people explore new worlds, or play games that put them at the center of action. Learn how we're helping users discover apps in the right context and powering new experiences with Daydream and Tango.

Fireside chat - Wayfair & Pokémon GO on augmented reality

Augmented reality engages and delights people everywhere. In this fireside chat, online furniture seller Wayfair and Niantic's Pokémon GO share their experiences with AR and discuss how other developers can make the most of the platform.

Building for billions, featuring best practices from Maliyo Games

Learn how to create apps and games for emerging markets, which are expected to drive 80% of global smartphone growth by 2020, by recognizing the key challenges and designing the right app experiences to overcome them.

At minute 16:41, hear tips from Hugo Obi, co-founder of Nigerian games developer Maliyo.

Launch smart on Google Play

Set your app up for success using experimentation and iteration. Learn best practices for soft launching and adapting your app for different markets and device types.

Apps

Sustainable growth solves most problems for apps, featuring best practices from SoundCloud & Peak

Planning and executing a great growth strategy involves a complex set of choices and mastery of many tools. In this session we discuss topics including key business objectives, tools, and techniques to help you solve the growth puzzle with our partner, SoundCloud.

Also, check out some growth best practices from Peak.

Creating sustainable user growth for startups, by Greylock

User growth isn't just about growing the number of users you have. The key to sustainability is creating and delivering core product value. In this session, VC Greylock discusses how to identify your core action to focus on and shows you how to use these insights to optimize your app for long term growth.

App engagement is the new black, featuring best practices from Lifesum

As the app marketplace becomes more competitive, developer success depends on retaining users in apps they love. Find out which Google tools and features can help you analyze your users' behaviors, improve engagement and retention in your app and hear insights from others developers including Lifesum.

Predicting lifetime value in the apps world

Deepdive into lifetime value models and predictive analytics in the apps ecosystem. Tactics to get the most out of identified segments and how to upgrade their behaviors to minimize churn.

Subscriptions update

Learn about Google's efforts to enable users, around the world, to seamlessly and safely pay for content. This session provides updates on Google Play billing and recent enhancements to our subscriptions platform.

Games

One game fits all, featuring best practices from Space Ape Games

Customize your game's experience for different users by targeting them with lifetime value models and predictive analytics. Hear how these concepts are applied by Space Ape Games to improve retention and monetization of their titles.

Promoting your game and growing your user base, featuring best practices from Seriously

Learn how to use Google's latest tools, like Firebase, for benchmarking, acquiring users and measuring your activities. Also, hear game developer Seriously share their latest insights and strategies on YouTube influencer campaigns.

Creating long-term retention, loyalty and value with engaging LiveOps events, featuring best practices from Kabam & Creative Mobile

Learn how successful developers keep their games fresh and engaging with Live Operations. In this talk, the LiveOps expert on Marvel: Contest of Champions discusses tips about the art and science of running an engaging LiveOps event.

Also check out the tips and best practices to run successful LiveOps from games developer Creative Mobile.

Panel - Play fair: Maintaining a level playing field in your game, featuring Space Ape Games and Kongregate

Ensuring that your game is fair is critical to success. Find out how game developers are achieving this and some ways Google Play can help.

Families

Why you need to build for families

Family-based households with children have higher tablet and smartphone ownership rates than the general population. These families are more likely to make purchases on their mobile devices and play games. Learn about how parents choose what to download and buy, and how you can prepare for maximum conversion.

Two keys to growth: user acquisition & app engagement, by Cartoon Network

Hear how Cartoon Network leverages their network to cross-promote new titles, acquire new users and keep them engaged through immersive experiences.

Go global: Getting ready for the emerging markets revolution, by Papumba

Papumba has a clear vision to grow a global business. Hear how they work with experts to adapt their games to local markets and leverage Google Play's developer tools to find success around the world.

Optimizing for a post install world

You've spent time and resources getting users to download your apps, but what happens after the install? Learn how to minimize churn and keep families engaged with your content long term.

Monetization best practices on freemium, by 01 Digital

Learn how 01 Digital uses In-App-Purchases (IAP) to effectively monetize their apps while maintaining a safe environment for families.

Building a subscription business that appeals to parents, by PlayKids

PlayKids has been at the forefront of the subscription business model since their inception. See how they best serve their subscribers by refreshing their content, expanding their offerings and investing in new verticals.



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06 December 2016

Saving Data: Reducing the size of App Updates by 65%

Posted by Andrew Hayden, Software Engineer on Google Play

Android users are downloading tens of billions of apps and games on Google Play. We're also seeing developers update their apps frequently in order to provide users with great content, improve security, and enhance the overall user experience. It takes a lot of data to download these updates and we know users care about how much data their devices are using. Earlier this year, we announced that we started using the bsdiff algorithm (by Colin Percival). Using bsdiff, we were able to reduce the size of app updates on average by 47% compared to the full APK size.

Today, we're excited to share a new approach that goes further — File-by-File patching. App Updates using File-by-File patching are, on average, 65% smaller than the full app, and in some cases more than 90% smaller.

The savings, compared to our previous approach, add up to 6 petabytes of user data saved per day!

In order to get the new version of the app, Google Play sends your device a patch that describes the differences between the old and new versions of the app.

Imagine you are an author of a book about to be published, and wish to change a single sentence - it's much easier to tell the editor which sentence to change and what to change, rather than send an entirely new book. In the same way, patches are much smaller and much faster to download than the entire APK.

Techniques used in File-by-File patching

Android apps are packaged as APKs, which are ZIP files with special conventions. Most of the content within the ZIP files (and APKs) is compressed using a technology called Deflate. Deflate is really good at compressing data but it has a drawback: it makes identifying changes in the original (uncompressed) content really hard. Even a tiny change to the original content (like changing one word in a book) can make the compressed output of deflate look completely different. Describing the differences between the original content is easy, but describing the differences between the compressed content is so hard that it leads to inefficient patches.

Watch how much the compressed text on the right side changes from a one-letter change in the uncompressed text on the left:

File-by-File therefore is based on detecting changes in the uncompressed data. To generate a patch, we first decompress both old and new files before computing the delta (we still use bsdiff here). Then to apply the patch, we decompress the old file, apply the delta to the uncompressed content and then recompress the new file. In doing so, we need to make sure that the APK on your device is a perfect match, byte for byte, to the one on the Play Store (see APK Signature Schema v2 for why).

When recompressing the new file, we hit two complications. First, Deflate has a number of settings that affect output; and we don't know which settings were used in the first place. Second, many versions of deflate exist and we need to know whether the version on your device is suitable.

Fortunately, after analysis of the apps on the Play Store, we've discovered that recent and compatible versions of deflate based on zlib (the most popular deflate library) account for almost all deflated content in the Play Store. In addition, the default settings (level=6) and maximum compression settings (level=9) are the only settings we encountered in practice.

Knowing this, we can detect and reproduce the original deflate settings. This makes it possible to uncompress the data, apply a patch, and then recompress the data back to exactly the same bytes as originally uploaded.

However, there is one trade off; extra processing power is needed on the device. On modern devices (e.g. from 2015), recompression can take a little over a second per megabyte and on older or less powerful devices it can be longer. Analysis so far shows that, on average, if the patch size is halved then the time spent applying the patch (which for File-by-File includes recompression) is doubled.

For now, we are limiting the use of this new patching technology to auto-updates only, i.e. the updates that take place in the background, usually at night when your phone is plugged into power and you're not likely to be using it. This ensures that users won't have to wait any longer than usual for an update to finish when manually updating an app.

How effective is File-by-File Patching?

Here are examples of app updates already using File-by-File Patching:


Application
Original Size
Previous (BSDiff) Patch Size
(% vs original)
File-by-File Patch Size (% vs original)
71.1 MB
13.4 MB (-81%)
8.0 MB (-89%)
32.7 MB
17.5 MB (-46%)
9.6 MB (-71%)
17.8 MB
7.6 MB (-57%)
7.3 MB (-59%)
18.9 MB
17.2 MB (-9%)
13.1 MB (-31%)
52.4 MB
19.1 MB (-64%)
8.4 MB (-84%)
16.2 MB
7.7 MB (-52%)
1.2 MB (-92%)


Disclaimer: if you see different patch sizes when you press "update" manually, that is because we are not currently using File-by-file for interactive updates, only those done in the background.

Saving data and making our users (& developers!) happy

These changes are designed to ensure our community of over a billion Android users use as little data as possible for regular app updates. The best thing is that as a developer you don't need to do anything. You get these reductions to your update size for free!

If you'd like to know more about File-by-File patching, including the technical details, head over to the Archive Patcher GitHub project where you can find information, including the source code. Yes, File-by-File patching is completely open-source!

As a developer if you're interested in reducing your APK size still further, here are some general tips on reducing APK size.

05 December 2016

Welcoming Android 7.1.1 Nougat

Posted by Dave Burke, VP of Engineering

Android Nougat

Android 7.1.1 Nougat!

Today we're rolling out an update to Nougat -- Android 7.1.1 for Pixel and Pixel XL devices and the full lineup of supported Nexus devices. We're also pushing the Android 7.1.1 source code to the Android Open Source Project (AOSP) so that device makers can get their hands on the latest version of Android.

With Android 7.1.1 officially on it's way to users, it's a good time to make sure your apps are ready.

What's in Android 7.1.1?

Android 7.1.1 is an incremental release that builds on the features already available on Pixel and Pixel XL devices, adding a handful of new features for consumers as well as optimizations and bug fixes on top of the base Android 7.1 platform (API level 25).

If you haven't explored the developer features, you'll want to take a look at app shortcuts, round icon resources, and image keyboard support, among others -- you can see the full list of developer features here. For details on API Level 25, check out the API diffs and the API reference.

You can find an overview of all of the Android Nougat developer resources here, including details on the core Android 7.0 Nougat behavior changes and developer features.c

Coming to consumer devices soon

We're starting the Android 7.1.1 rollout today, and we expect it to reach all eligible devices over the next several weeks. Pixel and Pixel XL devices will get the over-the-air (OTA) update, as will Nexus 5X, Nexus 6P, Nexus 6, Nexus 9, Nexus Player, Pixel C, and General Mobile 4G (Android One) devices. Devices enrolled in the Android Beta Program will receive the final version as well. As always, you can also download and flash this update manually.

We've also been working with our device manufacturer partners to bring Android 7.1.1 to their devices in the months ahead.

Make sure your apps are ready

Take this opportunity to test your apps for compatibility and optimize them to look their best on Android 7.1.1, such as by providing round icons and adding app shortcuts. We recommend compiling your app with, and ideally targeting, API 25. See our recent post for details.

With the final platform we’re updating the platform and build tools in Android Studio, as well as the API Level 25 emulator system images. The latest version of the support library (25.0.1) is also available for you to add image keyboard support, bottom navigation, and other features for devices running API Level 25 or earlier.

We're also providing downloadable factory and OTA images on the Nexus Images page to help you do final testing on your Pixel and Nexus devices. To help scale your testing, make sure to take advantage of Firebase Test Lab for Android and run your tests in the cloud at no charge through the end of December.

After your final testing, publish your apps to your alpha, beta, or production channels in the Google Play Developer Console.

What's next?

We'll soon be closing open bugs logged against Developer Preview builds, but please keep the feedback coming! If you still see an issue that you filed in the preview tracker, just file a new issue against Android 7.1 in the AOSP issue tracker. You can also continue to give us feedback or ask questions in the developer community.

As mentioned back in August, we've moved Android Nougat into a regular maintenance cycle and we're already started work on refinements and bug fixes for the next incremental update. If you have an eligible device that's currently enrolled in the Android Beta Program, your device will automatically receive preview updates of upcoming Android Nougat releases as soon as they are available. If you don't want to receive those updates, just visit the Beta site and unenroll the device.

Thanks for being part of the developer preview. Let us know how this year's preview met your needs by taking a short survey. Your feedback helps to shape our future releases.

01 December 2016

Indie game developers in Latin America sustain growth after launch on Google Play

Posted by Kacey Fahey, Marketing Programs Manager, Google Play

Indie game developers are some of the most exciting and innovative teams to work with. While developers large and small exist on the same field, gone are the days where you hit publish and turn your back, moving on to the next project. We've gathered a few developer stories coming out of Latin America sharing experiences and advice.

Oktagon Games

Ronaldo Cruz, Founder and CEO of Oktagon Games tells us how "reviews provide great qualitative insight on the game helping us identify problems that may not be caught by analytics."


Tiny Bytes

Tiny Bytes reduced churn by 5% using an in-game tutorial and analytics.

Impossible Apps

Cleverson Schmidt of Impossible Apps shares how introducing in-app purchases helps diversify revenue streams and "can make the game profitable and self sustainable."


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30 November 2016

Updated Udacity Android course prepares students for the Associate Android Developer Certification

Posted by Jocelyn Becker, Senior Program Manager, Android Training

As one of our most popular Udacity courses, the Developing Android Apps course was recently updated to ensure developers have the resources to build high quality apps. This course, which has already helped more than half a million developers learn to build Android apps, has been through the car wash and come out sparkling clean and updated.

Google and Udacity have worked together to update the course to include the very latest changes in Android and Android Studio, including how to use the new Constraint Layout editor, and how to use Firebase Job Dispatcher. Learn best practices for building Android apps using Android 7.0 (Nougat) while keeping your apps backwards compatible in older versions, learning at your own pace in your own time.

You sent us feedback that some of the lessons were a little difficult to get through, so we've restructured the lessons and added smaller apps for you to build as you progress through the course. So not only will you build the Sunshine weather app as a complete, integrated application that spans the entire course, but you'll also create an app in each lesson to help you learn individual concepts.

Build a To Do app and add new tasks as you learn how to build a ContentProvider.

This course brings back Android experts Dan Galpin and Reto Meier from Google, and Lyla Fujiwara from Udacity, and introduces new faces from Google and Udacity.

Start learning now at https://www.udacity.com/course/ud851.

Combined package for Developing Android Apps course and Associate Android Developer Certification

This updated course teaches the skills that are tested by the Associate Android Developer certification exam. Udacity is offering a package that combines the updated Developing Android Apps course with a voucher for the Associate Android Developer certification exam. If you pass this exam, you will earn the Associate Android Developer Certification and show that you are competent and skilled in tasks that an entry-level Android developer typically performs. Enroll in Udacity's Fast Track to get prepared and take the Associate Android developer exam at: https://www.udacity.com/course/nd818.

Learn tips from Memrise to increase in-app conversions with pricing experiments

Posted by Tamzin Taylor, Partner Development Manager at Google Play, & Kristina Narusk, Head of Production at Memrise

Getting people to install your app is one thing, getting them to sign up to your paid offering is quite another. It's important to understand the complete journey your users take from installing your app to paying for something. Once you do, you can experiment on the flow to try and increase conversions. Memrise has found great success in experimenting on their language learning app to increase the number of paying users.

Four experiments Memrise use to improve conversions

Memrise makes languages fun with a number of different learning modes you can play to help increase your vocabulary in a chosen language. You can download the app for free and play some of the modes or take advantage of their premium subscription offering called 'Memrise Pro' which offers new game modes and additional features like offline learning. Memrise recently ran a number of conversion experiments with the main objective of increasing the Average Revenue Per Daily Active User (ARPDAU). These experiments tested multiple user experience and pricing experiment scenarios.

1. A/B test how messaging different user benefits can impact conversion

What they did: Memrise wanted to know what motivation and call to action would convert the most users to buy a Pro subscription from a locked game mode in the app. To do this, they ran an A/B test with two similar designs, featuring different reasons for the user to upgrade, and compared the results to their original upgrade messaging.



Screen Shot 2016-10-11 at 15.26.00.png
Screen Shot 2016-10-11 at 15.25.34.png
Test A: Focus on ‘difficult’ words with an orange background.
Test B: Focus on ‘favorite’ words with a pink background.

Results: Test A performed the best. Conversion to Pro in Test A was 28% higher than in Test B. Pro mode usage was subsequently 9.7% higher in Test A compared to Test B too.

Next steps: After seeing how test A won the experiment, Memrise applied this creative across the board. Subscribers driven by that particular mode increased as a percentage of all subscriptions in the app by 16%. Memrise plans to run additional A/B tests at others points of conversion in the app to see if they can increase the results even further. They'll also try different text for the call to actions.

2. Test whether adapting to local price points results in sustainable uplift

In 2015, Google Play launched new minimum local price levels in countries around the world. To take advantage of the new price points, Memrise tested lowering localised prices in certain markets to better match purchasing power. Prices were an average of 6 times lower during this experiment.

Results: After 30 days, Memrise saw the following changes in conversions to paid users:



🇹🇷
Turkey
180%
🇧🇷
Brazil
182%
🇷🇺
Russia
99%
🇲🇽
Mexico
115%
🇮🇳
India
5.1%
🇮🇩
Indonesia
152%
🇰🇷
South Korea
120%
🇹🇭
Thailand
70%
🇲🇾
Malaysia
27%

Next steps: The change in price affected the subscription dynamics with more users taking advantage of Memrise's in-app discounted offer in most countries. The offer was for annual subscribers only and has led to a positive effect on LTV. One insight from the experiment was that Indian users prefered to have the option to subscribe in weekly or monthly increments and not just annually. Memrise is still tracking carefully to see whether the discounted subscription pricing will lead to an increase in conversions.

3. Test when and how often you offer free trials to see if that affects conversion rate

Memrise occasionally offers users, who aren't Pro subscribers, a free trial of one of the Pro game modes while cycling through the various free modes. After the free trial session, users are presented with an offer to subscribe. Memrise experimented with the offer's timing making it appear more frequently while users were cycling through normal free sessions Instead of after every 49th session, users saw the unlocked mode after every 21st session.



Screenshot_unlocked.png
Screenshot_unclocked_offer.png
An example of a free trial of a Pro mode.
After completing a free trial, users see a discounted subscription offer.

Results: Offering a free trial more frequently paid off. The conversion rate increased by 50% while all other conversion rates remained the same.

Next steps: Memrise maintained the more frequent offer cadence and has seen revenue growth as a result.

4. Test whether seasonal discounts result in more conversions Memrise launched a 'Back to School' campaign presenting all users with a discounted annual plan offer for a week in September 2016. The aim was to convert more users and generate higher value users from annual subscription plans.

Screen Shot 2016-10-11 at 16.03.14.png

Results: Memrise saw two effects from the seasonal offer. As a result of only presenting an annual period and removing weekly and monthly, 20% fewer users per day converted to Pro. However, because more people were taking an annual subscription than a shorter subscription, the average revenue per day increased by 32% justifying the change.

Next steps: Memrise plans to test different offers in the future with a combination of subscription offerings. They'll also focus offers in countries like Turkey and Mexico, where they saw the biggest increase in conversions.

Keep experimenting and take advantage of new features to improve the user experience and increase conversions

At Playtime San Francisco, we announced that introductory pricing for subscriptions would be coming soon and the feature is now live. By continually testing messaging, pricing, offers, and free trials or discounted trials, you could increase the conversions in your app and your ongoing revenue just like Memrise. Learn more about Google Play in-app billing subscriptions and get the Playbook for Developers app to stay up-to-date with features and best practices that will help you grow a successful business on Google Play.

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