Secret Watch

You can know the time by vibration without watching your phone.

ex.

* 3:10 -> 3 vibration + sleep + 1 vibration

* 7:37 -> 7 vibration + sleep + 3 vibration + sleep + 7 vibration

* 11:30 -> 11 vibration+ sleep + 3 vibration

* 15:10 -> 3 vibration+ sleep + 1 vibration

* 0:23 -> 12 vibration+ sleep + 2 vibration+ sleep + 3 vibration