Once you link Google calendar from Appointy, you will see all your calendar on Google Calendar.
Either create a new calendar with name "Appointy" or use an existing calendar with real personal events that has less number of repeat events. For example, if you have everyday repeat event "Lunch at 1:00 PM" then synchronizing it with Appointy will make no sense. Appointy brings only 100 future events and each repeat event is counted.