What is the timer that lots of runners use? (including any% wr)

Livesplit there are tutorials on youtube it is windows only I am pretty sure

almost everyone uses livesplit right now, there aren't really any alternatives that are as functional

I can recommend Livesplit as well

If you're on mac, I suggest using https://one.livesplit.org/ , which functions similar to Livesplit.

Most people use Livesplit, I personally use Wsplit because it's less CPU heavy.

Llanfair is the Mac alternative mostly used.

I use LiveSplit. It's free, easy to use, highly customizable, and responds to your button inputs easily. You can also make it Transparent on things like OBS, XSplit, etc. (OBS is SO much better than XSplit)

Download Links: LiveSplit: http://livesplit.github.io/ OBS: https://obsproject.com/ XSplit: Use OBS