UC Surface allows you to control the entire mixer from a Mac, PC, or iPad. You can make adjustments to the levels of the main mix or any aux mix, make changes to the Fat Channel settings, and dial in FX. QMix-AI is an iPhone/iPod touch control app for the aux mixes. It’s designed to allow musicians to control their own monitor mixes. The programs work together and are an excellent combination for mixing and recording live events.
Both applications allow you to limit the permissions to give an individual device access to only a specifically designated mix. This way someone can’t accidentally make changes to the main mix or someone else’s monitor mix without permission. It is also possible to limit a user to controlling the balance between their own channels (say, their guitar and vocal) and the rest of their monitor mix.