Volumio is a super nice free music streaming platform. I installed it into my Raspberry Pi 3. I did have some stumbles—my first install had Linux permissions errors. So I had to wipe it and set it up again. But when I got it set up correctly I found it to have a smooth and intuitive UI. I use it with Spotify premium (there is a Spotify plugin that makes this easy), and Apple Music (which I send to Volumio with AirPlay). I also like the fact that this software formats the digital stream for my hardware pipeline: I use an Allo DigiOne on the RASPI, and then a standalone SMSL DAC, which in turn sends an analog signal to my amp. This all works beautifully and sounds awesome. Thanks to Volumio for making it easy.