This means that an application will not be able to use future improvements to the action bar and it may feel out of place with the rest of the platform when run on versions of Android where there is a platform action bar available for use. ActionBarSherlock provides the full feature set of the latest built-in platform action bar to Android 2.1 and newer. All of the advanced features of the action bar work on Android 2.1 and newer without any additional effort: list navigation, stacked tab navigation, custom action item views, action item submenus, and action modes are available for use.