Not sure this is exactly the right category...

I have disposed of all FM tuners but still like to listen to some radio content.  The FM reception wasn't that great so when updating the home theater setup went for a soundbar as the primary sound source for the main family room. Love it to bits.  

Streaming radio and other content from a mobile phone or tablet is easy enough but is a bit of a pain when the device is needed elsewhere. 

I was thinking of setting up a dedicated phone or small tablet as a permanent controller.  Perhaps mount it on the wall with a power supply.  It wouldn't need to be anything flash, just so it can hold some local content (or access the home network) and have the apps for the different radio stations, spotify, iheart radio etc.  

I am concerned about having the device permanently plugged in and charging when all my wisdom is telling me to unplug a charged device to avoid overheating.  If I enclose such a device that would make the heat factor even worse.  

Anyone have any advice on what device could do this or alternatives?