I did the Vonage thing back when it first came out, then eventually landed on Ooma. Have had their service for -years- now. Basic service is “free”, as in $99 for the box initially and monthly fees amounting to about $4.

Airsonic (fork of Subsonic) has worked well for me for a few years. Used Subsonic for many years prior. I mainly use play:Sub on IOS for playback, local/offline caching, etc.