The Twitter Add-on is a Twitter API Library for WinAutomation, that allows you to automate any task related to Twitter. It includes a great collection of actions that can be used to virtually automate any Twitter-related task you can think of.
The downloaded file is a .wao file which represents WinAutomation Add-on files. To install it you will have to have WinAutomation installed on your machine, and then through the Tools Menu, and Add-ons Manager, press on the Install new Add-on button to install the downloaded file. To get a better idea of the Add-ons installation, please check out the Twitter Add-on Introductory video listed below.
The Twitter Add-on comes with a fully supportive Help file, where you will find detailed descriptions and examples for each action found within the Twitter Add-on.