The variety of media file formats is growing, but iPhone still only understands .MOV. There is a whole class of video player-converter programs for the phone. Here is another application for this purpose – Gplayer. This player plays video and audio of any format on the iPhone. And the GPlayer Lite version requires no money. Files are uploaded to Gpalyer through a browser on a computer via wi-fi or via iTunes. Already on the smartphone, you can create folders, rename, delete and move files. There are many settings for easy playback of movies and music. If you upload a subtitle file along with the video, they will be automatically detected and added to the movie. 
Supported formats: – video: XVID / DIVX AVI, WMV, RMVB, ASF, H264, MKV, TS, M2TS; – audio: MP3, WMA, WAV, OGG, FLAC; – subtitles: SMI, ASS, SUB, SRT, TXT Gplayer is compatible with iPhone 3GS / 4 / 4S, iPod touch 3rd and 4th generations and iPad. Required iOS – 3.2 and higher. The price of the app is $ 2.99.
GPlayer Lite [Free]
Install from AppStore
Gplayer
Install from AppStore