Here are a few of my preferred resources.
Desmos Graphing Calculator is a web-based calculator. It is very versatile and can plot functions in Cartesian, polar and parametric form. It is very intuitive. You can switch simply between degrees and radians and it is web based so there is no need to download any software.
Mr Barton GCSE Maths Takaway is a GCSE site of course with a lot of resources arranged conveniently by topic. It is a free resource and very popular.
Exam Solutions offers video instruction (short video clips) which are tailored to specific syllabuses. For those students who really need to see it done in real time rather than learn from the book, this is excellent. Many of my students have said that they like this website.
I tutor the International Baccalaureate Diploma in maths and physics. An excellent WordPress site is IB Physics Notes. It is very detailed and offers detailed revision material on all parts of the syllabus broken down by topic.
I also recommend Hyperphysics because it offers a clickable concept map showing all topics within Physics. It’s great for revision too.
Also thoroughly recommended is the inspirational site Physics Footnotes. This offers a large range of explanatory video clips that bring to life the principles in Physics.