Gosh. I just emailed myself a .png of the barcode containing my library card number and open it in, like, the Photos or Gmail app when I'm at the kiosk.
Same with event tickets. I define a location and timespan and when I arrive at that location, my phone will suggest the pass automatically without me having to look for it. Also, after the event, it won't suggest it anymore and move the pass to the "Expired Passes" section to not clutter the main view.
MakePass: https://pvieito.com