Boarding passes on a smartphone

[HereComesTheSun1]

Has anyone here checked in for a flight via a smartphone app?

If my friend checks us both in for a flight via a smartphone app and, therefore, has both boarding passes on her phone will we both be able to go through security, boarding etc with the boarding passes on the same phone (as long as we stick together) - or would I need to also download the app and have my boarding pass on my own phone?

It's Ryan Air, by the way, although I presume the process is probably the same whatever the airline is.

Can I also reassure you that if your phone runs out of charge or gets lost or stolen, you can simply go to the check in desk with your passport and they’ll print you a boarding card manually. I’ve done that before when my DD went through security without me and her sister, and had all the boarding passes on HER phone! EasyJet were very helpful.

I use my phone for boarding passes and tickets all the time both for me and sometimes for other travelers. I don't travel with Ryanair but I see no reason why theirs should not work.

For family travel we both have a full set on our phones because I am obsessed with backups. I was mocked for this as an obsessive (not entirely unfair) until DH forgot to charge his phone