Subler is an app for Mac OS X that makes adding captions on videos and saves files in MPEG4 format (. m4v,. mp4) to run on iOS devices. Captions can also be controlled directly on the iPod, iPhone, AppleTV, iTunes and QuickTime
The application uses online databases to update and add metadata information about the works. Subler can also be used as a transcoder or demuxer , depending on what you need.
With Subler you can, and insert subtitle tracks, open media files on it to add chapter titles, removing unwanted comments and include tags with information about the episode, the season etc..
The app is free, in English and compatible with Mac OS X 10.5 or higher