I’ve just joined https://mathsuccess.io and it’s the best elementary math program in the world! I’m actively open sourcing the entire curriculum and releasing it for free on github. We teach from a conceptual standpoint, using structural language and models, connections to real life, and kids grow and retain learning much better. The modeling, helps children see the math, understand conceptually what is happening and why, and then learning procedures is a breeze. What grades are you looking to start with?