It's a simple controller for DLNA browser and casting to Chromecast.
After NAS device to enable DLNA media service, you could also use this app to cast the media from NAS device to Chromecast.
It wasn't a great experience for me and a mate of mines we both downloaded this apo a long with a few others doing the same function or a very similar one which was a bit of a nightmare
It wasn't a great experience for me and a mate of mines we both downloaded this apo a long with a few others doing the same function or a very similar one which was a bit of a nightmare