FYI, some video conversion don't create videos playable by most broswers or os. Most mp4 videos can be played on iOS devices, but I would recommend m4v instead. Videos recorded on iOS devices are quicktime movies, and so you can convert them with quicktime. Regarding audios, our apps can record audios and played back on iOS devices. Alternatively, you can play mp3 on iOS devices, but m4a is also recommended.