These are my YouTube userscripts there are written for the current version of YouTube.
Remove Watched Videos
This will check the subfeed and remove watched videos.
Automatically Skip Adds
This will skip the ad before video as soon as the 5 second mark is passed. I am from germany and my youtube is in german. If you are from a diffrent country you have to change the const "equalText" to the text that is shown after the "wait 5 seconds to skip the add" banner. !!!CASE MATTERS!!!
I have written the script for Tamermonkey in Chrome. I don't intend to test it an any other browser. If there are issues let me know and i will look into it :-)
Download Tampermonkey Chrome extension
Click on the icon and choose "Add new script"
Copy the whole "*.user.js" and paste it in there
Save and have fun!
If you find something that seems wrong let me know!