This discussion is missing the biggest problem, which is that the underlying technology limits on Universal Apps is not acceptable to Roon.
We are not built on any Windows UI mechanisms, so using their UI technology is not an option at all. The entire Roon app is built on custom UI engine built on top of OpenGL. It’s why we are full featured on all the platforms we support.
Being a “responsive UI” is exactly what we’d be when we support phone sized displays. However, the work is all in the design and implementation of the UI (and product) for that smaller real estate. Just cramming the same stuff into a smaller screen doesn’t make it a good product.
When this work is done, iPhone and many Android phones should just work. Windows 10 phones and other phones not running iOS or Android will not work. If a phone out there let’s Roon run native C code, full non-neutered/sandboxed .NET CLR code, and provides good OpenGL 3.0 or OpenGL ES 3.0 support, then we can look into porting it there.
I’ve never seen Windows phone offer that, but then again, I’m not familiar with their latest.
Oh, and being a web app is not an option either (for now)… it would require a complete rewrite.