MathScore Freemium - Intended for individual families as well as classroom teachers with fewer than 30 students. Starts out completely free for an unlimited time, but with a limited selection of math topics. You then pay to upgrade each student to full topic access. First paid account costs $9.95/month, but the cost drops considerably for multiple students.
Can be purchased by Teacher, Student, or Parent. - We sell in-app upgrades and/or content (one-time)