Hi Tim,
Thanks for the interest in Watch support for play:Sub.
There has been very few requests for watch support until now, and not being a watch-person myself, I haven't had any plans for doing Watch-support any time soon.
If a lot of people find Watch-support interesting, I will definitely consider it sooner rather than later... and of course I'll have to get a Watch to play with myself

So iOS users: chime in on this thread or directly to me if you want Apple Watch support.
Cheers,
Michael.
Developer of play:Sub for iOS.
https://geo.itunes.apple.com/us/app/play-sub-subsonic-music-streamer/id955329386?mt=8