Did you ever think about the effects of autoboxing in your code? Or how about using attributes and annotations to make your code easier to digest for others? It's all covered in this week's issue of This Week in Mobile.

iOS 

If you’re worried about breaking language changes in Swift, you need worry no longer. The Swift Source Compatibility Test Suite is now available. Project owners can submit their projects to be included in the suite to ensure that as the language develops, compatibility regressions can be caught early. Nice work!  

When playing around with protocols and generics, sometimes things get a little messy with errors around associated types. Swift World: Type Erasure explains how to deal with this in a fairly neat way, with links out to other useful articles around the same subject.

While on the topic of protocols, here how you can Leverage Protocol Composition for More Maintainable Dependency Injection. It’s a very clear way to manage your dependencies in a Swift-y way. 

A really nice explanation of how to Optimize Your Code With Swift Attributes from the team at buddybuild. If you’re writing code that’s used by anyone else, this one is worth reading up on. 

Some projects to check out: 

• Cluster: Easy Map Annotation Clustering. 
• TweenKit: Animation library for iOS in Swift. 
• Fire-in-Swift: A delightful HTTP/HTTPS networking framework for iOS/macOS/watchOS/tvOS platforms. 
• BMPlayer: A video player for iOS, based on AVPlayer. 

Android 

Another key performance tip, and something I hadn’t thought about much before: how Autoboxing Can Cause Big Problems for Android App Performance. It seems to be easy to get around the drawbacks by using ArrayMap and SparseArray. 

Running interviews is really difficult, and it’s no different when Interviewing Android Developers. This article goes through some of the main topics you might want to discuss when looking for someone new in your Android team.

RxJava will always be a popular topic for any Java developers, so this article which compiles all the best resources to master the library in one place is a great idea. Enjoy The Complete Guide to Learn RxJava!

Custom Annotations can be pretty useful. Here’s a complete example of how to get your own up and running.

The team at Yelp show how they run Continuous Integration on Android using a cluster of AWS machines, and utilizing Firebase Test Lab to get some real testing done. 

Some projects to check out: 

• ExtraMapUtils: Utility library to make working wth maps more convenient 
• Meepo: Router generator for Android, similar to retrofit 
• ChromeLikeTabSwitcher: Provides a tab switcher similar to the one used in Chrome for Android 
• Matisse: A well-designed local image and video selector for Android 

General 

For some reason, it seems a lot of designers don’t use version control. Here’s how you can Run Smoother Projects With Sketch and Version Control, making collaboration so much easier.

Here’s some commentary on why having frequent app updates makes your app more competitive on the app store. Reducing technical debt is one good reason, but more subtle things, like being on the updates list more often, will remind your user base that you are still there! 

Finally, check out Creating Usability With Motion: The UX in Motion Manifesto, which explains how you can do so much more with an understanding of the twelve principles of UX in motion. It’s a long article, but the rewards will be great!