I am traveling back to Italy tomorrow but I forgot to print the boarding pass (I do have the PDF on my phone). I wanted to confirm whether I really needed to print it before going to the airport and that I cannot just use my phone. I have seen the other questions related to this but they seem to be very old.
Based on my personal experience: you cannot use pdf on your phone. But if you checked-in, chances are good that Ryanair won't charge you for printing your boarding pass. But don't do it at check-in counter, go to the Ryanair information counter.
Another option: you can try to print your boarding pass in a copy-shop at the airport if there are any.
I wouldn't trust them with a 10 foot pole. I have the boarding pass on my Ryanair mobile app, but I am an American citizen with residency in Spain and have a residency card which may not be enough for money grubbing Ryanair which threatens to charge 55 Euros or 55 pounds (around the price of my round trip!) to print out a boarding pass (much more than the much hated Spirit Airlines in the States).
I am printing off the boarding pass but will try the mobile app first and see what happens. This really sux because who has a printer nowadays? Everyone does everything with their mobile. If this airline were not so freaking cheap and did not go where I want to go, l would be willing to pay more and not be subject to their numerous indignities.
Ryanair will not accept a PDF of your boarding pass on a phone, and are notorious for charging a lot of money for printing boarding passes at the airport.
However even if you have already printed a boarding pass you can still use Ryanair's new mobile boarding pass app.
The link takes you to a page where you can select Apple, or Android/Google Play to download.