Formatters are optional and can be used to modify or change the value that is returned. Formatters affect both directions in data binding, ie read and write.
Formatters can be type specific, or handle all valid types.
Formatters can be one way, or two way.
Will add 1 when getting the value, but will subtract 1 when setting the value.
Formatters are a new feature and are currently being expanded. They will include formatting of dates, numbers, and much more.