This is a custom input control for iOS that enables the user to edit a number using a number pad.
The number pad only allows you to enter whole numbers. There is an undocumented decimal pad, which includes a decimal point, but then you need to set up a text field delegate to make sure the user doesn't enter multiple decimal points. And even then, you can't enter negative numbers.
On iPad, the number pad ought to be centered in the keyboard area. Also, there should be an option for it to appear in a popover view rather than as a keyboard.
The field should intercept keyboard input. Right now it updated the text field, but not the internal data store.