It is a cuckoo clock app that specializes in the use of a voice-over.
You can be informed of the time in the cries of the cuckoo every hour on the hour and every 30 minutes.
App screen has to like make settings directly.
I am using the iOS notification function.
If, when the time signal does not ring, please make sure the items in "Settings" app> "notification"> Cuckoo VO.
Note that you can also use in those who are not used in the voice-over.