I used to not have a banking app too but my bank made me ;-(

They started to require to type my own account password into websites to be able to pay via credit card! Incredible but true. As this was of course completely unacceptable I resisted for as long as I could. But at some point I had to use my credit card on a website with no other option (it was for a collective present, I couldn't select another website; I could not participate but that would have been incredibly rude and unkind).

It's not too horrible though. The app is much less bad than I expected.