Subler

Subler is an Mac OS X app created to mux mp4 files. It's forked from http://code.google.com/p/subler/ and mainly the creation of damiog. The main features are:

• Creation of tx3g subtitles tracks, compatible with all Apple's devices (iPod, AppleTV, iPhone, QuickTime).
• Mux video, audio, chapters, subtitles and closed captions tracks from mov, mp4 and mkv.
• Raw formats: H.264 Elementary streams (.h264, .264), AAC (.aac), AC3 (.ac3), Scenarist (.scc)
• iTunes metadata editing and TMDb and TVDB support.

about this fork

this fork is an "anime-friendy" one, which means it prioritizes the Japanese language over all others for tracks and also will support MyAnimeList and anidb