Shuttle uses the native media player that comes with your phone, so as long as a filetype is supported by your phone, it is supported by Shuttle. Supported Media Formats

Why does Shuttle seem to use lots of RAM?

Shuttle is a very image-heavy app. The images are kept in a ‘memory cache’ so they can be efficiently displayed on your screen, without too much delay. This cache can fill up quickly causing the app to use upwards of 200mb of RAM. This is not a cause for concern, RAM is there to be used!! Anyway, if your device decides it needs more RAM for any reason, Shuttle will drop the images from the cache and free up your memory immediately.