The following is a list of user plugins that can be either used as is or alternatively serve as inspiration on how to write your own.
This plugin allows four physical buttons to be mapped to a single virtual hat. The mode, virtual hat, and four physical buttons can be configured by the user via the UI.
This plugin allows the configuration of a circular deadzone which applies a radial deadzone around the center of two axes and a box deadzone around the edge. This results in a deadzone which looks something like the following: