I know I've been talking about this forever but there's finally a real MIDI controller app for Windows Phone and it's free. It's actually not the first but that first one didn't look terribly useful anyway.
It's called Meedy Wifi. Sure... it's not good looking but I can see the beginnings of a useful app in this.
Instead of using already available wireless MIDI software like rtpMIDI, Xavier Malparty decided to make his own and it's small, simple and straightforward. It's available here http://wp7.malparty.fr/
It still would be nice if it could communicate with rtpMIDI (without Bonjour) though.
Obviously this will be quite easy with a Win8 pro tablet because it can run all kinds of software that already exists for Windows but it would be nice to have something on Windows Phone that's at least as nice as TouchOSC or midipad. The ultimate one right now seems to be http://mididesigner.com/ but that's hoping for allot at the moment