I'm a historic transport enthusiast from the south of England. I'm keen to improve the many Wikipedia articles on historic transport in the UK, especially having seen that many of them have so few references (often to broken links or sources that don't meet Wikipedia guidelines) and inline citations. I'm trying to use my book collection, and online sources such as the Commercial Motor archive, to improve the referencing in particular, and in some cases add additional information. I'll willingly admit that I still have a lot to learn, and will make mistakes - please be gentle in correcting them!
install user customized JavaScripts (a simple cut/paste operation) into your user page's vector.js or monobook.js skin. Installing to your common.js subpage will allow both skins to use a single JavaScript installation.
As you can see, tools are implemented in a number of ways. There are tools available for many different purposes, and with many different functions, and some that are multipurpose. Many of these are explained at Wikipedia:Tools/Browser tools, which includes a list of tools, for each major browser.