Yup, just been discussing that with another user in pm.
It's absolutely blimmin awesome. I'm very traditional with my guitar methods - not usually struck on electronics. Tubes and valves are more my liking. But I bought it anyway.
Costs a tiny fortune ( you'll need the iRig connectors too ) but boy is it fantastic. Obviously doesn't replace a full on rig with pedals and amps, but comes very close to it. The sounds is very good. Very authentic. And it includes in-app purchases like Fender cabs, recording desks, various stomps boxes etc etc. Most professional. Well worth the £30 or so quid it's so far cost me.
The sound can then be output directly through your headphones, computer or guitar amp (another cable needed for this tho).
Makes garage band look like a toy