Calculate in-flight rest periods fast and easy using only one finger.
Check the time on the aircraft clock (utc).
Add sufficient time for the first rest period to start and select it in the wheel "Rest Start"
Check the FMS for the ETA (utc) and select it in the wheel "Landing"
"Margin before landing" is the margin in minutes between the end of the rest and the landing. It will depend on whether the last relief pilot flies the plane during the landing or not (As per ICAO recommendation). It can be from 00 up to 100 minutes (TOD is usually 20 minutes before ETA). Select it according to your preferences pressing the buttons +/-.
For the cabin crew conveniece the margin can be set to 0 to allow no margin with the last service.
Select two or three periods (3 or 4 pilots) and data will be calculated.
If you are happy with the calculated periods, you may modify the courtesy time that every pilot requires from the wake up call before returning to cockpit.
Use the +/- on the iPad or tap over the courtesy time on the iPhone, to cycle from 0 to 20 minutes, in five minutes gaps.
Last, if you want to be called either at the start, wake up or end, switch on the wakeup call for the desired periods. The iPad/iPhone will send you a notification even if it is on standby or the app is on foreground.
Remember to accept notifications when installing the app or modify in Settings to allow the notifications for Periodactilo. Otherwise the app will not be able to send any notification even if you select it on.