Short:

PS Vita homebrew plugin that lets you change the way buttons behave in game

Tech:

C, reverse-engineering, Sony SCE lib

Links:

Github, Article at wololo.net

Taihen (game) plugin for PS Vita, that lets you change the way buttons work (i.e. remap one button to another).

It consists of two parts - a configurator application, where you can setup your assignments, and which will then make an actual plugin (configuration of which is directly embedded into the executable file) that you can use in the game.