DroidUPnP is a simple UPnP/DLNA client for Android devices. The UI is simple and modern. It was able to detect my ReadyMedia server and I was able to browse its contents.
However, it struggled to open renderer for my content and I could not find a good music player interface. This was a deal breaker for me.
Tried with: DroidUPnP 2.3.0, Android 5.0.2 and Moto G2 (XT1068)