how much data are they supposed to be collecting from inside an android app that basically takes a credit card payment and displays a QR code?
Ryanair at one point at least had their margins such that every penny a passenger spends other than the ticket was profit, so they actually have less incentive to do this than some of the other carriers.
I'll never let companies like Ryanair execute code on my devices. I don't care how well it works.