Nobody I know uses that app. They charge way higher admin and booking fees than the alternatives.
Trainline adds a fee to every ticket sold, apps like TrainPal do the same things as Trainline (book tickets, check delays, see platform, walking times, etc), but only charge a fee if they get you the ticket cheaper than buying it from the station. So, including the fee, the price you pay is still less. And it find way better split-ticket deals than Trainline does.
the fee is usually less than £1. Every single person I know in the UK that travels via train uses it. I wish it didn't fall to a private institution to provide what is a fairly basic service, but I think the fee shouldn't deter people from using it, especially considering they don't even charge it in a lot of cases. Booking tickets directly with a ToC is a terrible experience.
Trainline adds a fee to every ticket sold, apps like TrainPal do the same things as Trainline (book tickets, check delays, see platform, walking times, etc), but only charge a fee if they get you the ticket cheaper than buying it from the station. So, including the fee, the price you pay is still less. And it find way better split-ticket deals than Trainline does.