I am running iCPro on iPhones and an Android tablet (Nexus-7).
To get into Cue mode click on the up-Chevron in to top left corner of iCPro and then click on the schluessel icon above the Mixconsole icon. then select wich types of track you want to see and also select Cue Mix and then 1,2,3 or 4. Finally click on the ‘+’ icon in the top right corner to get back to the fader view.
It does not seem to be possible to show only the active Cue Send channels, but the faders will only adjust the selected Cue Send levels - your main mix levels will not be changed.
BTW, how exactly are you running iCPro in your browser?