I’ve spent a lot of time researching UPnP control devices for my Chord Poly and I really like Glider as it seamlessly integrates music on UPnP servers and my iPhone. The only issue is that it doesn’t find renderers or servers when the phone is in hotspot mode. I’ve done some research into this myself as it seems to be common amongst UPnP control apps and a lot of open source libraries available search only for “en” devices but the iPhone interface name when in hotspot mode is “bridge” so it should be quite a quick fix to change this. I’ll happily pay for the full version if this feature is implemented
Also, it’d be nice if selecting shuffle when browsing albums shuffled by album instead of song as I miss that feature from my old iPod, but that’s not a deal-breaker!