App | Category | Revenue ($M) | Users (M) | Launch Date | |
---|---|---|---|---|---|
Chegg | Education | 716 | 7.7 | December, 2007 | |
Busuu | Education | 39 | 1.5 | January, 2008 | |
Babbel | Education | 170 | 10 | January, 2008 | |
Memrise | Education | 18.5 | 2 | September, 2008 | |
Duolingo | Education | 531 | 74 | June, 2012 |