Estimated income: $17 million from “Sweat with Kayla” app alone, $150,000 per Instagram post

Instagram followers: 8.6M

Kayla Itsines’ interval workout regimens may not be revolutionary, but she leveraged an enviable body, #transformation pics, and an achievable lifestyle into a true fitness empire. The social media star is known for her “Bikini Body Guides” ebooks and fitness app “Sweat With Kayla,” which earned the most revenue of any fitness app in 2016.