How to play webm file in iOS video player

I want to give support of webm file in iOS , but iOS doesn't support this format to play a video. i Even tried to play it through HTML5 video tag but safari doesn't support webm format in HTML5 video tag that means i also cant make it work through UIWebView. But i have seen an app that is supporting this format in their media player , that means there should be some way.

Thanks in advance for help!