Haven't used the Shell app yet despite having one if their sites nearby that is usually quite competitive. Their app seems a little clunky & the need to set a max transaction beforehand is annoying.
It's a shame that Trainline charge booking & creditcard fees otherwise I'd use them more often. I always buy direct from the train company - with Virgin Trains East Coast, you generally get a free wifi voucher when booking their advance fares direct with them and no fees to pay.
It is a shame, definitely.
I looked at Virgin Trains on Monday for a fare in December from Birmingham through London.
Went to book it directly with them yesterday and the fare had risen hence the visit to Trainline.
In a way I don't mind paying the booking fee (there was no credit card surcharge unusually) as I know my details are slightly more secure instead of entering my details directly and running the risk of having the account compromised and used fraudulently.