UnityPlayerActivity of a Unity Android application is responsible for basic interactions between the Android operating system and the application. You can use plug-insA set of code created outside of Unity that creates functionality in Unity. There are two kinds of plug-ins you can use in Unity: Managed plug-ins (managed .NET assemblies created with tools like Visual Studio) and Native plug-ins (platform-specific native code libraries). More info
See in Glossary to create your own Activity that extends and overrides Unity’s default
|Create a custom activity
|Extend the default Unity activity to control interactions between Unity and Android.
|Specify Android Player command-line arguments
|Specify startup command-line arguments to pass to Unity.