Stay away, they are bad news! 
I booked two return tickets last night applying my rail card. Within 10 minutes I realised that my rail card had also applied to the second set of tickets and this would have been incorrect. I tried to change this – impossible (and I ‘am’ techi), so I was made to apply for a refund. So for a £7.65 ticket they were charging £4.99 administration charge!!! With Trainline this would’ve been easy, just thought I’d take advantage of the £10 off offer they were showing for First bookings… which also didn’t materialise! Stay clear of TrainPal