Drop.js is built on Tether. It has been made especially to create various kinds of dropdowns and tooltips. There isn’t much else to be said about it other than that you should definitely be using it!
Get Drop.js on Github
Shepherd guides your users through your website. It is also built on Tether and it dims the rest of your app while providing a tooltip-like popup that points at an element on your website, giving some extra explanation about the element or feature while giving the user an “exit” and a “next” button to go to the next step.
Get Shepherd on GitHub
It comes with a start, stop, resume and reset function, as well as a callback for when the animation has finished.
Get countUp.js on GitHub