Megacast - Chromecast Video
This isn't strictly a Chromecast app, but rather than Android one that you'll need to download on your phone. Regardless of how you get it on your TV, through, Megacast is an excellent Chromecast player that has real-time transcoding support, allowing you to play files from your phone or tablet that aren't supported natively on your individual Chromecast device. This includes AVI, MKV, 3GP files and more. It can also automatically pre-load subtitles or let you add your own, making it one of the most flexible video streaming apps around
The Google Chromecast lets you display video, photos, pictures and other media content from supported apps on your big-screen TV, using your Android or iOS device as a remote control. You can also send content straight from a Chrome Web browser on your computer. There are hundreds of apps that take advantage of this unique technology, which Google calls "casting," to offer a new way to link.