During the year of 2011, I think I could see how it was very popular. Currently, there are so many ways to keep reminders or to communicate. I think it would be important for an app to be user friendly for all ages. Although the numbers you presented, “over 23 million active users including educators, students and parents and over 90% of US K-12 school districts are using the app.” is quite interesting. I like the analogy of riding the bike. It is important that the founders personal experiences has been taken into consideration. Thanks for this post!