APIInterface - An interface for official API documentation
As I bumped into the in-game API documentation in 7.2 I found it rather annoying to use as it's all stuck in chat. So I end up making an addon that takes the documentation and presents it in an easy to navigate window. As it uses the official API, it also keeps itself up to date, unless they add a new feature such as the events.
It uses a style similar to achievements. By default it shows all the systems available. Clicking one of them shows all functions, events, enumerations, and structures in that system. If you then click one of those it shows the documentation and an editbox where you can ctrl v the clipboard string.
I've also added 4 buttons to search for different types in _G. So if you're looking if a certain function exists that's not in the documentation, or a localized string, you can just type something in the searchbox and click one of the buttons. It will show the results in a separate /tableinspect window