Whether your business is mobile or salon grooming, you can use "Send ETA" or "Ready for pickup" to keep communication with your clients.
On a pop-up appointment detail screen, click on "Pick up reminder",
Set up: (no special set up needed, when you click on "pick up reminder", this is the pop up window that you can type message).
From mobile app:
On the appointment detail screen, click on Contact > send ETA
Set up: （you can set up the message template)
Setting > Send ETA > Edit message