Simple Unity3D build script

BuildScript.cs

public class BuildScript
{
    static void Android()
    {
        BuildPipeline.BuildPlayer(GetScenes(), "your.apk", BuildTarget.Android, BuildOptions.None);
    }

    static string[] GetScenes()
    {
        return EditorBuildSettings.scenes.Where(s => s.enabled).Select(s => s.path).ToArray();
    }
}