3GP Audio Converter
- Convert M4a to MP3
- Convert M4b audio books
- High quality and free
3GP is a container format developed for mobile phones. It can contain both audio and video data, like MP4.
As usual, take a look at the "Quick Start" section to see how the files can be converted, or simply drag and drop 3GP audio from your favorite file manager and hit F5 (or click "Convert" on the toolbar). Set a custom folder for saving converted files, adjust MP3 parameters, if needed.