In no particular order: freesciencelessons, cognito( + cognitoedu.org website), any CGP/Collins Revision guide + check out the GCSE Study resources on quester.io.
Finally as a side note, i would whole-heartedly recommend that you make flashcards on Anki.
Anki is a flashcard program that implements active recall and spaced repetition into your learning and there are so many research papers highlighting that that is the best approach to studying known so far by cognitive neuroscience.
Good luck with your studying!