Here is a fun project based on libpd and thus pd : ppp.mgsx.net
This work is based on a fork of droidparty by Chris McCormick : it helps you to build binary apps for android, and include a standard wifi MIDI clock in your patch, meaning that every app published with this framework can be synched with one another, or even any other kind of MIDI compliant music gear.
We still have some documentation to write up, but we have a good start as well as a video and a few sample apps available for free in the android playstore.
This is somehow related to this old post : http://forum.pdpatchrepo.info/topic/5496/running-your-patches-on-android-usind-pddroidparty-in-10-steps
I hope you like it as much as we enjoy making it, have fun !