Just a quick tip — in Gig Performer, for a widget to work bidirectionally over OSC
Give the widget a handle – I typically use handles such as Knob1, Slider1, Button1 for the first knob widget, the first Slider widget and the first button widget respectively.
If a widget has the handle Knob1, then the OSC address for that widget to set the value of the widget will be /Knob1/SetValue
In TouchOSC (or any OSC application), when you add a knob, there will be a place where you specify its OSC address and you would use /Knob1/SetValue
Then once you have the TouchOSC device and the computer connected together with the proper IP address and ports, the widgets should synchronize.
All that said, are you aware of this post where someone created a very good TouchOSC interface to work with Gig Performer already?