I don’t know how to revise for GCSE Spanish VocabWatch
If your examboard has a specific vocab list in their website, I suggest you base it on that. I would use quizlet as you can revise them really effectively or you could cut pieces of paper with English on one side and Spanish another and put it in a box or something and revise from that
You could sign up to Duolingo. This helps to refresh any vocab you may struggle with. As well as this, you could write down the vocab you are struggling with and get someone to test you. Hope this helps.
In terms of vocab, quizlet is great for refreshing your memory and learning new vocab. In terms of learning new vocab, I generally find that lyricstraining is better as it forces you to use vocab that you do and don't know, as well as helping a lot with your listening exam. Everyone has a couple of words that they can just never seem to remember, so if you discover any like this I'd recommend making flashcards with a picture that goes with them.