SMS Reminder for Google Calendar automatically sends SMS text, email, and voice
  reminders to your clients and customers based on your Google Calendar appointments.
  Just add a phone number to any calendar event and reminders go out on your schedule —
  no manual effort required.

  Built for businesses, not personal use. If you run a practice, salon, clinic, or any
  appointment-based business, this add-on reduces no-shows by sending your clients
  professional reminders before their appointment.

  How it works:
  1. Connect your Google Calendar (takes 60 seconds)
  2. Add your client's phone number to any calendar event — in the title, description, or
   notes
  3. Reminders are sent automatically via SMS, email, or voice call at the times you
  choose
  4. Clients can confirm, cancel, or reschedule by replying to the text

  Key features:
  - Automated SMS, email, and voice call reminders
  - Two-way messaging — clients confirm or cancel by text reply
  - Confirmation status written back to your Google Calendar event
  - Custom reminder templates with your business name and details
  - Multiple reminder timing (e.g. 48 hours before + 2 hours before)
  - Works with personal Gmail and Google Workspace accounts
  - Multi-provider support — connect multiple calendars
  - HIPAA compliant with signed BAA available for healthcare
  - Online booking page so clients can self-schedule

  Trusted by 2,500+ businesses worldwide. Dental clinics, healthcare practices, salons,
  consultants, and service businesses use Appointment Reminder to reduce no-shows and
  save hours of phone calls every week.

  14-day free trial. No credit card required.