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.
Upload components
HTML5 is a new HTML standard developed to add multimedia support to HTML. It is supported on Windows, Mac OS X, Linux, iOS, Android, and Windows Phone. 
Since the format is still under development and some of the features employed for uploading files are still not part of the standard, HTML5 upload components are not common at the moment. Their support is restricted to a subset of browsers.