1- If you incorrectly enter the master password the second time you try to enter it you cannot tap on the lock to unlock, the button stays disabled and you have to use the 'Go' button in the keyboard to submit the password. Maybe it's intentional?
2- The textfield for the quick unlock code is off-center, a little towards the right side.
3.- If you go into the edit mode in the categories tab all the elements move towards the right as if they were going to show the delete button. I think it's unnecessary to have that animation since you can only reorder them, not delete them. Although I'm not sure, maybe you can't disable that animation…