This is a very minor issue indeed but, given the effort you have put in to polish the UI, I thought it worth mentioning.
The text "Enter Quick Unlock Code" appears to be positioned oddly in the unlock screen input field on iPad.
I think it should either be centred in the field or made consistent with the prompt for the Master Password:
On the iPhone, the text is centred in the box and I think this is the most pleasing appearance except that the insertion point appears at the left of the text and, when you start entering the code, the insertion point shifts to the middle of the box which feels odd.
How picky am I?