Adobe Flash Player
Steve Jobs also claimed that a large percentage of the video on the Internet is supported on iOS, since many popular video sharing websites such as YouTube have published video content in an HTML5 compatible format, enabling videos to playback in mobile web browsers even without Flash Player.
MuseScore
MuseScore.com allows playback of a score in any browser supporting the HTML5 audio tag. A score can also be linked to an online video, so that one may follow the sheet music while watching a video featuring that score.