Hey Harryhat and any others having issues.
Here is the solution that tech support gave me from a different App I use, same applied to Amplitube for me as I looked at these settings:
"Maybe you did not set to allow the App to access your microphone. iOS 7 added privacy setting for microphone access, it will ask your permission when first time start-up.
You can go to the
iOS setting -> Privacy -> Microphone to enable. Make sure it is enabled for "Amplitube" and any other apps in which the Apogee Jam or other interface is not working."
I would never have figured this out, I was amazed how they had that hidden this, but once I checked above in Settings I realized the Mic was off for Amplitube and a couple other Apps where I could not get the guitar in.
Overall I also find my Apogee Jam not as good in the ipad apps after iOS7. May just be me but I dunno but sound is not as professional which is why I may be looking to go iRig HD route
Let me know if you need more help, let's hope you get it working for the gig Saturday.
BTW, I would love to know how you guys are finding the iRig HD. I would mainly use it on my iPad as for my Mac rig I have a dedicated Audio Interface. Anyone tried vs Apogee Jam etc?