Curve is a really cool app that lets you put all your cards into one place and can easily change which account will be debited through the app
This is also cool you can keep all your loyalty cards in one place which is preety cool as well (I think this is probably one of its better features)

But what your really here for is the free money
so if you sign up using link
make one payment with your curve card you get a free 5 pound straight into your account to spend
To be honest wiht you I only set up used the £5 (to buy some bounty chocolate bars) and then havent used it again since the wallet on my phone kind of does the same job but perhaps if I had more loyalty cards I would use it more, but nice little treat before christmas.