>For what it is worth, at least on iPhone you can still use the bus/train pass feature in Wallet even when the battery is dead.
AFAIK that only works for NFC passes? For passes that are just qr/bar codes I can't imagine how that'd work if the battery is actually dead. The "use bus passes when battery is dead" feature only works because there's dedicated low power circuitry to power the NFC hardware, which obviously doesn't exist for the display.
It depends on the details. Last time I flew I used the airline's app to get the ticket which were then immediately loaded into wallet and read via NFC at the gate.
But this is Ryanair so it's probably going to do some stupid QR thing that will be super touchy and be a struggle to work on at least half of the devices. Bonus points if the app refuses to start if it can't make a live internet connection back to some cursed cloud service so the people waiting in line who accidentally let their phone go to sleep find they can't get it to show the ticket in the dead zone at the gate.
You need the app to download the pass (AFAIK) but it goes into your Google/Apple wallet after that. I have the app disabled (so it can't run in the background, as much as possible), and I only use it to get the pass.
I wish they'd just let me download a pkpass file, but what can you do.
But it has always been the Ryanair brand to ask the consumer "how much bullshit are you willing to put up with to save a buck?"