Android development: By default, this workload includes the core Visual Studio editor, the C++ debugger, GCC and Clang compilers, Android SDKs and NDKs, Android build tools, Java SDK, and C++ Android development tools. You could choose to install the Google Android Emulator in the Optional Component list if you don’t have an Android device for testing. This should give you everything you need to start building Android applications.
iOS development: if you’re also targeting iOS, check “C++ iOS development tools” in the Optional Component list and you would be good to go.
Visual Studio to target all mobile platforms
If you’re building an app to target multiple mobile platforms (Android, iOS, UWP) and wish to share the common code in C++, you can achieve this by having one single Visual Studio solution and leverage the same code-authoring and debugging experience all in the same IDE. With Visual Studio, you can easily share and re-use your existing C++ libraries through the shared project component to target multiple platforms. The following screenshot shows a single solution with 4 projects, one for each mobile platform and one shared project for common C++ code.