If one is going to use a smartphone to control it, why not just stream directly from the smartphone to a Bluetooth or WiFi speaker?

Does it have installable apps, or fixed functions for each (current) streaming technology?

We still have a few old Squeezebox 3 units in service, which still stream Internet radio just fine. We often use an iOS app to remote control them, but the plastic remotes also work for quick volume changes and station selection. It is nice to have a simple dedicated display showing what song is playing.

AirPort Express from Apple allows AirPlay from any Apple device to a powered speaker. I use them to stream Apple Music plus anything else that plays on iPhone/iPad. Output is not just analog audio, digital optical audio comes out of the same 3.5mm jack.