The ACT has overtaken the SAT as the most widely used college admissions test. The SAT is a "general reasoning" exam that tests math, vocabulary, reading comprehension, grammar, and writing skills. The ACT, however, focuses evenly more strongly on specific subject knowledge and tests math, reading comprehension, grammar, and science.
Knowsys helps you master the skills you need to succeed on the ACT. Knowsys can even help you with the optional writing component.