GBCal is an independent calculator app you can use on your Apple Watch.

O You can enter number by slip and touch gestures.
- 1: down slip
- 2: 1 touch after down slip
- 3: 2 touches after down slip

O Clear number from label
- slip left: one number
- slip right: all numbers

O Also number can be inputted by slip and consecutive slip.
- 1: slip down
- 2: slip right and down consecutively
- 3: slip left and down consecutively