To be clear, the technique of messaging in a special code to a number to "subscribe" to a service has been around for many, many years before edtech companies started using it recently. But it's a good approach.

And there's one big difference: services like Remind101 offer broadcasting, but they don't allow the students to reply.

We're out to open up and optimize the communication between teachers and students. Over time, each side will get the tools that serve them best. That's why the UX is web-based for teachers and SMS-based for students.