Excellent! My only problem with it is that the added search engines don't get synced by Firefox, so you have to manually add them again if you uninstall and reinstall the browser.

Very useful. Awesome.

Da pra add quantos mecanismos de pesquisa quiser aos padrões do firefox (q já deveria deixar add por padrão)

I'm really happy with this addon. It's very easy to use. I only had one issue, so far — I tried to add an .ico file as the icon and for some reason it didn't work. But, I tried adding it another way (I downloaded it to my computer and then browsed to add it) and then it worked. I've used the searches without any issues thus far. It's exactly what I wanted and needed. It really adds on the functionality that I was looking for. Thank you very much to the developers! :)

Норм добавляет любой сайт в поиск но не ватает поддержки андроид версии и жаль что нельзя задать поиск через гугл или яндекс по сайту

Something to be ware of (as noted when using the addon): it uploads your custom url to file.io due to a technical limitation in Firefox...

Poorly support. Author will close your issues and ignore errors. It allows you to use invalid (unsupported by firefox) image formats.

This is awesome! I missed Chrome's search engine handling when I migrated to Firefox and this extension has filled the void perfectly. It also shows that even such a simple extension can be really pretty! :)

Was great when it worked. Nowadays, I get an error each time I try to add a new search engine: "Firefox could not download the search plugin from:
https://file.io/XXXXXX". I have switched to the "Search Engines Helper" which also uses file.io, but works fine on my system.

UPDATE: in response to dev's question: I can visit that file.io page with no problem. The Search Engines Helper addon also uses file.io as yours does, but it works for me.

UPDATE 2: Note that I can actually manually access the file.io URL that the "download error" dalog gives me by entering it in the URL bar -- I see the source of the XML file. Hope that helps!

UPDATE 3: After updating to new version (1.8), all is working properly again, so I have revised my lowered rating to reflect my true opinion of this very useful add-on.