With two of three UK GCSE Mathematics papers still to go at the time of writing, I can see the various revision pages are popular. The GCSE (14-16) Revision page has been updated since last year; notable additions include:
From David Morse, Maths4Everyone has a wonderful collection of high-quality resources, all freely available on TES Resources. Note all David’s fully worked exam questions by topic.
Also on Maths4Everyone, you will find a lovely collection of GCSE Revision Worksheets including a great set of SSDD revision questions. (See Craig Barton’s SSDD Problems site.)
On Maths Genie, you will find numerous resources by topic. Under Grade 7, for example, we have Inverse and Composite Functions. You will find some revision examples and also exam questions with solutions.
For centres offering International GCSE qualifications, you will find the brilliant Maths Emporium team have been busy with the filing cabinets.
Note that all the exam boards add examination papers to their secure sites; these should, of course, be kept securely, they are intended only for teachers. They should not be shared.