I finally bought an iPhone 4S, yay!!! I bought a few apps then every time when I try to sync apps to my Mac, iTunes pops up saying it wants to delete my apps
It took me a while but I finally figured out how to sync my apps to my Mac:
In iTunes => under Devices => right click on my iPhone and click on “Transfer Purchases from”.
iTunes would start copying the apps to my Mac.
Once done, I can then tick on “Sync Apps” without a problem.