Originally Posted by
blind pew
From what I understood when I tried to buy one is that I still had to get one printed from the station ticket machine..or maybe I was trying the wrong app as it didn't give me the choice of using my phone for travel.
It may depend on the app. The Trainline app gives a little pop-up to say mobile tickets are available, so acceptance may have changed. Not all tickets are available digitally. Anything with a TFL travelcard or cross London journey has to be printed on ticket stock, so if you were going beyond "London Terminals" you would have required a ticket in any case.