Enable Subtitle when watching movie in iPhone

A little-known feature of the iPhone is its ability to display subtitles on movides. To do this, you just need the free programs MKVtools, SubCleaner, and Subler, and a conversion program — I recommend FilmRedux. Once those are installed on your Mac, do this:

1. Convert the file to a raw, unsubtitled .MP4 with FilmRedux
2. Extract the UTF8 subtitle file (.srt) from the original file with MKVtools
3. Clean up the .srt with subcleaner
4. Merge the .mp4 and the .srt together in subler

Then sync the movie over to your iPhone. Next to the rewind button, a new subtitle button will appear.