This week we have UI design kits, getting app store reviews right and tracking the essential metrics for your app. That's on top of the usual mix of coding articles and projects that you should check out for your app. 

iOS

Natasha the Robot gives an Introduction to Protocol-Oriented MVVM so that you can avoid subclassing and use protocols instead.

If you feel the need to do some UI prototyping for your iOS app in Sketch or Illustrator, you can get this Free iOS 9.3 iPhone UI Kit.

View controller lifecycle behaviours allow you to do to add reusable functionality to your controllers. It's worth taking a look at how this is done.

Building Popular Projects 

Here are some Swift projects for you to try out: 

• SubtleVolume: Replace the system volume popup with a more subtle indicator

• ReplaceAnimation: Pull-to-refresh animation in a UICollectionView with a sticky header flow layout

• navigation-stack: Stack-modeled navigation controller

• PeekPop: Peek and Pop with backwards-compatibility (preview content using 3D touch or long presses on older devices) 

Android 

Check out the start of a series of Android Studio protips, including how to clear your app data quickly and analyzing a stack trace.

Have you started using Kotlin to build Android apps? If it's on your horizon, check out this two-part series on Building a Kotlin Project (part 1, part 2) 

I'm sure you've been looking forward to hearing more about the N Developer Preview. Here are some Random Musings. 

You know dependency injection is the right thing for your app, but you're not sure which library to use, and what the implications are? The people at NimbleDroid have spent some time Comparing the Performance of Dependency Injections Libraries to save you from having to do so!

Here are this week's project picks from GitHub: 

• BottomBar: A custom view component that mimics the new Material Design Bottom Navigation pattern.

• ExpandablePager: ViewPager that slides vertically

• Android-Templates-And-Utilities: Collection of source code, utilities, templates, and snippets for Android developers

• password-view: A Material Design password view that toggles password visibility via an eye icon.

• EventBus: Event bus that simplifies communication between Activities, Fragments, Threads, and Services. 

General 

App reviews - a necessary evil if your app is going to succeed. It's so hard to get reviews, and when you get reviews you need them to be good ones! Here is some advice on How to Get Reviews in The App Store the Right Way.

I love this article from Nick Babich which talks about Mobile App User Engagement: Breaking the Wall. So many apps have sign-in screens before you can try out the app.

My day job is all about information, data and metrics. If you're starting out on the journey of tracking mobile app metrics, this is a great list to start with. If you manage to get your metric list to also intersect with this list from Andreessen Horowitz, you can at least be sure you're tracking the most important things.

Developers, I'll leave you with this talk on The Empathetic Developer from dotSwift 2016. Michael May talks about inheriting legacy code bases, and the self-centered attitude some people take to this. There's a reason that all code gets unwieldy and out of control, and it's rarely done on purpose or to annoy you!