Remind is a text messaging service I use to send out information about our class. This can include:
Assignment reminders
Grade updates
Schedule reminders
Schedule Changes
etc...
I work very hard to keep the messages to a minimum, typically just a couple a week, depending on your level.
Using Remind is not required to be successful in class, but most successful students do seem to use the service. I have saved more than one student for missing or late work!