Google Chromecast Audio: Stream your favorite music with Google Chromecast Audio. Simply plug into your speaker's auxiliary input and connect to your Wi-Fi network. Then just tap the Cast button from your favorite apps on your phone, tablet or computer to cast songs, radio stations and podcasts to your speaker.
pro: good for multi-speaker synchronization casting easy to use works okay for primary purpose
cons: does not have bluetooth --- meaning will not work with music that don't support google cast (except android) for music streaming with android, the packet loss ( from interference) is much worse than bluetooth. I believe this is due the inherent design of WiFI vs. bluetooth (more resistant to interference). However, this makes music streaming, even with android, pretty useless. when trying to streaming audio of a video, there is always a delay, unlike with bluetooth the above mentioned flaws makes this device extremely limited in usage scenarios -- i.e. if you only want to listen to music with google-cast only app, then it's okay. if you don't need multi-speaker synchronization, don't get this device.