I cant help you on the XCode thing, but.. from my experience, never tell anyone how you've found it out. I've often have had students who delivered "bad" work b

I cant help you on the XCode thing, but.. from my experience, never tell anyone how you've found it out. I've often have had students who delivered "bad" work but I still have to give a fair mark for it. So I always asked "have you written your assignment at 2am yesterday night? or, why is it so bad?" If they've said "no, i've worked since a week on it" then, I hiddenly looked at the file's metadata "creation time" - aaaaaaand... 3am - file created - 4am last change of the file. Then I looked deeply in their eyes and said "I've have a hidden talent... I can see it in your eyes. you started at 3am and stopped at 4am. So, what mark would you give yourself for such work, if you compare it to others?" ... If they say "no no.." I just answered "you're lying to me. Be honest to me and yourself.." ... and so on. The mark then have a punishment for lying built in. I explicitly tell this the students. It can be appealed agaist, but then some proof of the students version is needed. This makes them afraid of cheating.. or, at least, be honest about that. check on meta-data of the file, then you know when. and then you can derive out of experience, if the time needed for the assignment is much longer than Now minus .xuserdatad creation time - then, one can assume its done by a experienced professional. And then you can use the psychologic trick to get the information you want..