You can convert video files to audio files (MP3, AAC) with various options ( bitrate, meta data)
1. Supports various types of videos (3GP, FLV, MP4, MKV and so on)
2. Supports various types of audio (MP3, AAC, OGG and so on)
3. Supports import video or audio from Camera Roll or Files
4. Supports custom bitrate, sample rate, volume;
- Fixes crash bug while transfer over WiFi
- Fixes pop view dismiss with batch mode on iPad
- Fixes other minor bugs
Volume Booster 
VConverter - The Best Video or Audio Converter 
Super Cloud Video D/L Player 