ACT offers a free study guide and online practice test designed
to help you get the best score possible on the ACT test.
The free official practice test is offered is all four subject areas and
includes links to resources to help improve your skills. You can retake the
practice test as many times as you would like.
https://www.act.org/content/act/en/products-and-services/the-act/test-preparation/free-act-test-prep.html