If you've ever been stuck between two icons for your app, it seems that iOS 10.3 might be the release you needed! Find out more about this in our iOS section.

iOS 

One really useful addition to Apple's Human Interface Guidelines is these Sketch and Adobe Generator resources containing all UIKit controls. While a number of templates like this exist, it's nice to get one from the source of it all! 

iOS 10.3 will include a way for developers to add an alternate app icon. Interesting, but not the most useful thing ever. Also, the end user will need to give permission for the icon to change.  Here are some more details about how it works.

Map is one of the most useful parts of the Swift language; this article takes you through everything you need to know about it, along with some short examples. 

Tired of hanging around while your Swift build is running? One cause of this is being addressed in Swift 3.1 where large bridging headers are present in the project.

Some projects to check out: 

• Fiber2D: Cross-platform 2D game engine in pure Swift.
• SwiftyStoreKit: Lightweight in-app purchases framework
• Timepiece: Intuitive date handling in Swift.
• CalendarKit: Fully customizable calendar for iOS.

Android

There's nothing like the satisfaction of finding a design pattern that fits for a problem you've got in your app. Here's a great list of Common Design Patterns for Android.

You've got to be careful with the hardcoding of secret keys in your app. In We reverse engineered 16K apps, here's what we found, you'll see that it's way more common than you'd expect.

It can be a little more challenging to add tests for the user interface in an app, but it's worth considering at least; see TDD Your UI Layer for more. 

If your app is becoming a bit of a memory hog, you should take some time out to make things more efficient. Maybe you can follow the example set by this app that reduced its memory footprint by 50%.

Read these Two Fatal Myths About Winning Google Play. If your app isn't doing as well as you had expected, maybe these have something to do with it!

Some projects to check out: 

• android-state: A utility library for Android to save objects in a Bundle without any boilerplate.
• StatusView: Custom status view for Android.
• MovieGuide:  Movie discovery app showcasing MVP, RxJava, Dagger 2 and Clean Architecture.
• Store:  Android Library for Async Data Loading and Caching.

General

If you've been looking for an start to end list of what you need to consider for an app, be sure to read The Ultimate Guide to Creating a Mobile Application.

Dealing with colors in your app seems like it should be easy, but without a natural flair for these things, it can all go wrong. To save yourself the embarrassment, check out Color in UI Design: A Practical Framework.