Ultra Mobile 3GP Video Converter is a video file conversion app that can convert many common video file formats into 3GP, 3G2 or MP4 files, which are more suited to mobile phones. It also has some ability to scale file resolution and quality, and it can play back videos in the app, though this feature is not perfect. It does require some effort to use, such as specifying where converted files should be output, and conversion can be slow on some computers or devices, but this does not significantly hamper the app's usability.