If this page automatically opened up in a tab, then I am happy to say that your Add-on User Style Manager just got updated to version 1.0 which brings about a whole new level of awesomeness on top of Version 0.9. You can find the add-on hosted on AMO and also a direct link to install it here.
Here are the main and important changes from version 0.9:
- Styles installed from userstyles.org are now automatically updated in the background with full control to whether overwrite any local changes or completely disable auto updating.
- Styles installed from userstyles.org are now synced betweed your synced Firefox’s.
- That means that when you install this add-on to a new machine (lets say work) that is synced with your home machine’s Firefox, then all the styles would automatically be ported to your new machine within seconds.
- You can even choose to keep the styles that you deleted on your other Firefox.
- Style Editor window is now a proper window. That means that it can remember positions, sizes and what not.
- You can now install/write even more variety of Styles that effect the internal UI parts of Firefox, like scrollbars, etc.
- Visit this page on github for a full list of solved issues in this release.
Visit the features list page to see all the features of User Style Manager.
Many thanks to Drugoy and Alepopeo who helped in testing the features and finding out bugs. Alepopeo also made some nice UI changes and feature requests that we will work on and have a major User Interface revamp in version 1.1.
Thank you all for using my Add-on. As always, post any issues or feature requests on the github page here : https://github.com/scrapmac/User-Style-Manager/issues
Leave a comment below if you like my add-on and spread the word 
Great. Planet Mozilla informs me of a nicely-written, restartless userstyle manager that just gained Sync and auto-update support… and I prefer the Stylish UI’s about:addons-integrated UI too much to switch.
Great job on the restartless and sync, I guess? (For now, I’ll be sticking with Stylish and installing the Stylish Sync extension I just discovered)
No worries
I mentioned in my post that Version 1.1 will have great UI revamp.
You are very welcome to switch then
The new automatic updating of the styles is very automatic indeed!
Straight after the addon got updated, it updated my styles and all my modified styles were overwritten without any kind of notification. And I’m fully certain that it even updated the ones that did not need any updates! On top of it the backups were exactly the same as the new updated styles. All my modifications are now gone. At least I’ve old FF profile backup that contains some of them in Stylish, which means I have to import all them again to your manager. I will do it as I like your manager a lot more. It has a really great editor and I appreciate all your hard work you have put on it.
My requests,
add opt-out from automatic update option for styles and make the automatic updating disabled by default.
change the “Ok” to “Update Anyway” when checking updates and it prompts “the styles doesn’t need updating”.
make the backups more reliable with automatic updating.
Actually, if you open the Manage window, and click on the Update Menu, you will see an entry called “Overwrite local changes”. Make sure that you have it unchecked and from now on, your local changes will never get overwritten.
I apologize for the one time loss that you had as prior to this version, there was no way for this add-on to know that the style has been locally changed. The check for local changes is introduced in this release only, which means that now that you have ported back the styles, they will never get overwritten again.
Thanks for sticking to the add-on, but this changes was important keeping in mind what is in store for this add-on in the future.
Thanks for your reply! I understand, the automatic updating is a must have feature that I was excited to hear about myself. I just wanted to share my first time experience with it. The checking for local changes is also a great feature, and it should do what I requested as the opt-out from automatic updating.
After using your manager there is no returning back now. It’s much better and it has a pack of new great features. The loss of the few modifications wasn’t a big deal. I have already restored most of them. And good to hear that I don’t have to be afraid of loosing them again.
Also, I noticed that the scrollbar styles are working now, great job on that!
All the best, can’t wait for the next version and its surprising new features!
I love this add-on and it makes me change my main web browser from Chrome to Firefox.
I enjoy changing the default ugly Korean font to my favorite one overall websites with “@font-face”.
Thank you!!
and Any plan to making chrome version??
Not in near future as I am totally not familiar with how chrome extensions work