Android software development is the process by which applications are created for devices running the Android operating system. Google states that “Android apps can be written using Kotlin, Java, and C++ languages” using the Android software development kit (SDK), while using other languages is also possible. Some programming languages and tools allow cross-platform app support (i.e. for both Android and iOS).The official Android app distribution mechanism to end users is Google Play; it also allows staged gradual app release, as well as distribution of pre-release app versions to testers.
Android development – Career

You can make a very competitive income, and build a very satisfying career as an Android developer. Android is still the most used mobile operating system in the world, and the demand for skilled Android developers remains very high

It is worth learning Android development in 2020?

By learning Android development, you open yourself up to many career opportunities such as freelancing, becoming an indie developer, or working for high profile companies like Google, Amazon, and Facebook. The demand for native Android developers is still very high, and learning Android development has never been easier thanks to increases in online learning materials.

Android SDK Platform Tools

The Android SDK Platform Tools are a separately downloadable subset of the full SDK, consisting of command-line tools such as adb and fastboot.