DN: I always found Apple's Keynote to be a really great tool for designing, animating, and prototyping. I created a course + UI Kit with many popular app examples to show how I do it. There is a free chapter (you can just click preview in the syllabus below).
Let me know if you have any questions.
I was just looking for a basic UX course and, well — there it is, right on your website. Waiting for that early access ;)