This is a sample movie listing app. It makes a network call to get the most popular movies and then displays it in a list. Each item on the list is clickable and takes the user to a detailed page with a (non-functional) "Buy Tickets" button.
I made the following decisions when writing it:
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Kotlin Android development is clearly moving towards Kotlin and away from Java. Kotlin provides better protection against Null Pointer Exceptions than Java as well as a more readable syntax that eliminates boilerplate code.
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Retrofit While the official documentation for Android uses Volley for network requests, Retrofit is more widely used. While not completely used in this example, Retrofit is set up to work more seamlessly with Kotlin coroutines than Volley is.
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Glide There are other newer alternatives for loading images, but Glide is extremely easy to use.
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MVVM Until recently there has not been a clear winner in terms of code architecture on Android. Various companies tried different approaches (MVP, MVC, RIBS, etc), but lately the industry has settled on MVVM as the de facto standard. This approach allows business logic to reside in the ViewModel which allows for more easily unit-tested business logic.
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Dagger/Hilt Injection While Dagger was easy to use for Java-based back-end servers, in Android it was more difficult, because Android hides access to constructors, which makes it difficult to inject objects directly Hilt (and the Kotlin view models library) largely fixes that with annotations that make it easier for Android developers to use it. Since the Injection is done at compile time, this makes it superior, in my opinion to KOIN.
This app is simple enough that there isn't much to test. There isn't really much in the way of business logic in the Model. If I was working with QA on this, I would make sure they tested that network outages wouldn't crash the app, and that the images and data loaded properly.