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 User Agent Switcher by Curiosity
Rated 4 out of 5 stars
This extension works with SeaMonkey 2.21, but I had to bump up the max version to get it to install.
It would be nice if the list of fake user agents included the other parameters that can be entered into the editor other than just the UA string for the browser's header.
To create your own collections, you must have a Mozilla Add-ons account.