While I never fly on Ryan, the question here would be whether, as the article suggests but isn't completely clear, digital boarding passes are actually app-only

While I never fly on Ryan, the question here would be whether, as the article suggests but isn't completely clear, digital boarding passes are actually app-only, or whether, like most airlines, you can get an image boarding pass from the website or by email that is meant to be displayed on a phone. App-only would be dubious.