iWatch app for a Dental Clinic - Intercommunication system

Concept - Staff will register everyday in the morning so consider 3 to 4 people will register - and if they want to call anyone during the day they will just go to the watch screen and find the person from the list of the person who has registered in the morning - will touch the screen from the list - and the person will get the alert and notification in the form of vibration ( 5 seconds ) - if person replies by touching the watch then it won't create another vibratory alert if didn't respond in 10 min then again alert will happen automatically. Simply if hygienist wants to call doctor for the check up they won't interfere during the treatment and they can just create a vibratory alert. I am open for any cheaper options in the form of vibratory technology. let me know if you don't understand.