Alpha 15 adds the ability to cast to any device that supports the cast api (like the chromecast). This also marks the completion of the last major feature from 2.x that was missing. There are still a few smaller capabilities (outside of customizations) that are missing, but those are not nearly as much work as the major features. GMMP now implements the cast api 3.0, so this means the volume rocker will now change the cast volume..... sometimes. On my one test device it seems to random change what volume it is controlling. I will look into this further and hopefully have a solution for the next alpha. One thing to note is that since I ended up updating some of the libraries, it really messes up the UI until you either clear the cache or change the theme. I put a check in to manually reset the theme if upgrading from a previous alpha to this one and it seemed to fix things on the device I tested on, however if the UI basically looks like its split ...