The Ulster Bank mobile app is good IMO, one code to get in and a large amount of history viewable, click for more details within the transaction etc.
I have an AIB acc as well and find the mobile app not as clear to read as regards what's a credit tran and what's a debit, and also AIB seem to take longer to reflect Visa debit trans.
Agree with OP, PTSB's app is rubbish and the main site isn't great either, I use it for my brother and its a pain compared to UB or even AIB