Khan Academy for Test Prep?

Hello, I’m planning on retaking the ACT in July. I’ve taken both the ACT and the SAT and I felt like the ACT was a better fit for me. I got 6 months of free test prep for the SAT and my question is should I just use this to prep for the ACT? And it’d also be helpful to get some tips on good websites to use for test prep since there is so many. I mostly need to focus more on math and science, the rest I did pretty well on and I know I can do better going into it a second time.Thank you!