I`ve been using Gas Cubby for at least 2 years. Since there was iOS 7 update, i cannot sync anymore. It happens like this:
1) I press the sync button;
2) A message appears: "Verification Needed: Due to a change in iOS, Gas Cubby needs to reactivate this device before syncing";
3) Then i just press the button to send the verification email.
Now, my iPhone just close the app and nothing more happens.
I tried everything from reinstall the app until reboot all my achieves.