I think the iC Pro app and the CC121 could have synergies together.
If you make it possible to see all available channels in a list, or mark a track by touching a fader in iC Pro. Then it would be quick and easy to choose a channel to control with the CC121. Instead of choosing a channel in Cubase with the mouse, choose a channel in iC Pro and control it with the CC121.
Also the user knobs and EQ could work together with the iC Pro app. You could forexample use the user knobs to control plugins using the iC Pro app in conjunction with the CC121. And see the built in EQ in the app, and see it change while knobs on the CC121 is turned.