I have a little trouble with appointments+
I use it with GCal API mode bidirectional. If a client cancel an appointment from frontend [app_my_appointments allow_cancel="1"] or email cancel link, this appointment show as cancelled into A+ backend, but in GCal this appointment dont dissapear.
So we dont know if a client cancel an appointment with GCal view....
If I cancel this appointment manually from A+ Backend, appointment is deleted from GCal Correctly!
How i can solve this critical problem, if we can not sync these cancellation we dont have a reliable version of GCal and become unusable