Try it for free! If you like it pricing starts at $9 per month. SMS Reminder allows you to send SMS reminders to your customers using Google CalendarâĒ, you can customize the scheduling of the SMS to be sent an 1 hour before, 1 day beforeâĶ, you also can customize the sender and the content of the message. Itâs really easy to use, each time you create an appointment you have the option to add your customer phone number and thatâs all. Try it free and start reducing no-shows now!