Sure there is: https://github.com/escabe/org.escabe.mysonos I just don’t think it is very useful for many others.
The basic thing I wanted to have is: if alarm sounds, group bedroom, bathroom and living room speakers together and play a radio station on that group. Then if I stop my bedroom speaker, I want the living room speaker to continue playing.
This was not possible before: there was no “bedroom stopped playing” to trigger on; my App implements that. Also there is no good reliable way to first remove a speaker from a group and then have that speaker play something…with the current Homey Sonos App, this typically results in the old group playing instead of that speaker I had just ungrouped…unless I add some delay of at least 10 seconds, but I don’t want that 10 second gap in audio. My App implements a new action which ungroups the livingroom speaker and once that has been completed, specifically tells that same speaker to resume playing again.
As you can see though if you look at the sources, I hardcoded the way in which I indentify the living room and bedroom speakers.