Ableton/loopy/zoom g3/amplitube midi/looping question

[monster_inc]

Hi all,

I am a singer/songwriter/guitarist and I am looking to try out a looper set up. What I would like to do is to add a layer or two in verse/chorus format. For example, verse, chorus (with pattern 1), verse, chorus (with pattern 1 and pattern 2), bridge, chorus (with pattern 1). 

I've watched a demo on the looper in Ableton with a footswitch. It looks like stepping on the footswicth the first time starts recording, and stepping on it again stops recording and starting overdub. Is there a way to assign midi footswitch so that on second press it stops recording and doesn't start overdubbing/replaying? 

Similarly, can this be done on the IOS app loopy? 

Separately, I have had a look at the zoom g3 manual and it looks like there is no such function. Is this correct?

I am also curious to know if a midi footswicth can be set to control more than one app on IOS, e.g., amplitube and loopy. 

Thanks in advance =)

P.s. I don't own any of the above but I have access to an iPhone and will have a copy of Ableton Live 8 Lite.