OSC2MIDI is a flexible osc <-> midi bridge written in C and designed especially for control of jack midi apps from an android device. It was created with the open source android app Control (OSC + MIDI) in mind, since thats what I use, but was deliberately designed so that one can specify any arbitrary mapping of messages for conversion with plain text files. The default mapping works with well with Control but I also have included maps for adrosc, touchosc, and generic osc messages. Mapping is (in my opinion) extensively documented in the map file default.omm included with the source so you can quickly create your own map to suit your own needs.