I quite liked studymaths.co.uk/ when I was doing my exams. I thought this website provided clear revision, and a nice past paper bank. It also contains ALL of the formulas that you will need, as I'm pretty sure that GCSE's no longer get the formula (or at least a limited formula content), unlike previous papers. This can really help to see them all in one place, so it is easier to actually apply them to your work. It also has a 'game' feature, in which you can test your maths skills by playing games. I know - a little cheesy, but I thought that it was a bit nicer than sitting there doing past paper after past paper . I do think this is rather catered if you are looking to access the higher grades. I used this a lot, and got an A* in maths. Another one that was favored by other pupils in my class was s-cool although I didn't particular like this one. But, it's up to you which you find best to revise from.
I hoped that this has helped - and good luck with all of your exams! x