Curve is a smart card app to put your finances in one place. You can have it as a digital only or receive a physical card. Very handy for adding all your loyalty cards in one place too.
Signup with this link for £5 to spend anywhere:
www.curve.com/join#NV5ZKKON
Select the curve blue card which is free, and you can also use to earn cashback and elimate currency conversion fees.
If you add a bank card, £5 will then be added to your "curve cash" balance which you can spend on anything you like. Just be aware if you spend over £5 or it'll charge your card rather than the balance.