Kotlin

Google Pay is Google’s mobile payment service. We can use Google Pay make a tap-to-pay in physical stores, and we can also purchase goods in apps. In addition, Google Wallet can manage credit cards, so we don’t need to carry several credit cards.

Android Collection Widgets are used to display many items of the same type on the home screen, such as picture collections, mailing lists, etc.

Android App Widget is an extension of app. App can provide a piece of information or a simple function through app widgets without requiring users to launch the app.

For some reasons, we may want to prevent users from taking screenshots of our app. In Android, we can use WindowManager.LayoutParams.FLAG_SECURE to achieve this effect.

Hilt is a dependency injection library based on Dagger and designed for Android. So when developing Android, using Hilt will be more convenient than using Dagger.