Apps similar to EloMath include Khan Academy, which is free. Other options are Brilliant.org and mathigon. In total there are three Online Education Services like EloMath for the web, Android, iPhone and iPad.
Khan Academy is not-for-profit with the goal of changing education for the better by providing a free world-class education to anyone anywhere.
United States
Brilliant.org, also known as Brilliant, is a website and associated community that features problems and courses in mathematics, physics, quantitative finance, and computer science.
United States
Discover Mathigon, a groundbreaking new education platform that adapts to every individual student. Mathematics has never been so colourful.
