When teachers want to talk to parents of their students, they used to write a letter. On that letter, parents would fill in when they are available, bring back the letter to school. The teacher then checks if that works out. If it doesn't, another piece of paper travels back to the parents to pick a new date, and so on and so on. That's why I created a Google Forms Add-on to automate this process. Parents just open the form, pick a timeslot an BAM... The add-on informs both teacher and parent that the appointment is made and that's it. The selected timeslot gets removed from the Google Form so no other parents can pick that same timeslot. Easy Peasy!