Calm Radio presents the latest addition to Android TV. The Kodi (formerly XMBC) is a great open-source platform app you can add Calm Radio's app.
Kodi/XBMC has become one of the best home entertainment systems available, and all for free.
Originally called XBMC (Xbox Media Center) it has evolved leaving behind the hardware limitations of the original Xbox and changing its name to Kodi.
Kodi can be installed on many things from a cheap Desktop/ Laptop to a Raspberry Pi. There are even hacks for an Apple TV.
Dedicated media center boxes and Android sticks can also be bought. If you don’t want to install and setup Kodi yourself than there are several to choose from.
Please read these self-help guides on using a Kodi.