Android apps are designed to run on devices that use the Android operating system, which Google developed. These apps are typically written in Java or Kotlin programming languages and can be installed on smartphones, tablets, smartwatches, and other devices that support the Android platform.

Android apps are available for download through various app stores, with Google Play Store being the most popular and official source. They come in a wide range of categories, such as games, productivity, social networking, health, and many more, providing users with a rich ecosystem of apps to choose from and customize their devices. Developers can create and distribute their apps using the Android Software Development Kit (SDK) and Android Studio, the official integrated development environment (IDE) for building Android apps.