For any questions on UACC or TouchOSC, check out these links:
Spitfire Audio has created a new articulation switching method, known as the UACC (Universal Articulation Controller Channel), to be used as a standard across their libraries.
It's currently at v2.
For more information on the nuts and bolts of how it works, and the philosophy behind it, please see these links:
UACC - A New Proposed Standard
Tutorials - Spitfire Audio - Changing Articulations
Current UACC spec v2
TouchOSC is an app for iOS and Android that relays OSC or MIDI values to a host DAW (via TouchOSC Bridge) over WiFi or USB.
Users may make various templates for their instruments/projects via a desktop program (TouchOSC Editor), and upload them to the mobile device that will be used as a controller.
For more information on how to setup TouchOSC, TouchOSC Editor and the TouchOSC Bridge applications, please see:
* Don't forget to select "Locked to UACC" in the Kontakt performance view of each patch you load to use with this.