I have used it a few times and have been on the receiving end of my son't teacher's texts. There are a few reasons I like it:
1. It sends the texts from a number that is not your own.
2. Students/parents cannot reply to your Remind text.
3. You can choose which classes you want to receive your text.
4. Texts can be scheduled to be sent out at a later time.
There are a few ways students or parents can sign up: you can send them directly to Remind's website and they can use the code specific to their class, print out a QR code, send them an email invite or have them text a Reminder phone number with the class code in the message.