An animated book
Equations you can see and move. Change a number and the lines, planes and arrows move with it; drag the picture and the numbers follow.
Based on MIT OpenCourseWare 18.06, Linear Algebra by Gilbert Strang, used under CC BY-NC-SA 4.0. Retold, redrawn and animated by Papermorph; this book is shared under the same licence. Not affiliated with or endorsed by MIT.
Every work cited in the lessons.