I'd suggest revision dojo and revision village - mainly just practice questions tbh, I don't think you need too many resources for math. just make sure you're solid on content through your teacher, yt vids + textbooks, then focus on practicing even just a little bit daily! I think ive said before the grade boundaries are usually low for math in the final exams so don't worry too much about the grades you're getting in class :)
aww I'm so happy to hear that!! 🫶🏼 I didn't apply to the US so I don't know much about common app unfortunately, but let me know if you have any other video ideas :))