To try the thousands of add-ons available here, download Mozilla Firefox, a fast, free way to surf the Web!
CloseWelcome to Firefox Add-ons.
Choose from thousands of extra features and styles to make Firefox your own.
CloseReview for Scriptish by David.P
Rated 1 out of 5 stars
Scriptish did nothing when presented with this userscript:
https://greasyfork.org/en/scripts/21391-youtube-comments-sidebar
Also, there were absolutely no instructions about how to install a script.
Greasmonkey otoh instantly recognized the script and installed it with a nice dialog and after one click.
So I went with GM and uninstalled Scriptish.
To create your own collections, you must have a Mozilla Add-ons account.