Unfortunately, I can't find your closed superuser question.
The question as you citate here, is probably far too general. But, if you ask from a specific problem in a specific browser addon, there it will be ok.
To find the wanted addons, you can use the http://softwarerecs.stackexchange.com .
Thus, what I would suggest:
- Separate your question in two different parts.
- Ask for the usable add-on on the softwarerecs.
- Your question would be probably closed as duplicate (very likely it was asked already a lot of times there), but the dupe will give you probably a lot of browser addons for the task.
- Download them, try them.
- Go back with your, this time more specific problems to the SU.
I found the SU and also the softwarerecs quite friendly sites, fulfilling their criterias will be probably easy. They are not the hairsplitting line in the moderation.
Now @BenN 's comment showed me your closed SU question. I think it can be done only on a site-specific CSS/JS insertion, which for your specific problem probably doesn't exist. But, with a little CSS/JS experience, you can probably develop your own. So, first you have to on the softwarerecs SE, where you can find such browser addons. Second, you have to implement the CSS/JS insertions for yourself. In your case I would use firefox/firebug/greasemonkey for the task, but in chrome I am not sure.
If you find a problem in the CSS/JS things, you can get help on the stackoverflow.
You can also host your code on the github.
The SU hasn't to do anything with this whole.