Excited to share something I have been working for over a year in my spare time - an e-book of visual essays titled "Linear Algebra for Programmers" - https://www.linearalgebraforprogrammers.com/ (not optimized for mobile devices yet)

It starts with taking a weighted sum of numbers (and then vectors/arrays). Everything else builds up by just observing and interacting with weighted sums of arrays.

Hope you enjoy it.