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.

This is the simplest and also the best extension of its kind, and the only ready-made solution for custom search engines since pre-Quantum times. The icon feature is excellent. As mentioned previously, the ability to export settings would make this even better. Thanks for this solid add-on!

Perfect !

Love it! Life-saver

best

For some reason, I had not seen the blue magnifying glass the first time around. This time it worked and I managed to add the search engine that other add-ons could not add properly.

Does what it says. Would be nice to have an export function too, for easy website implementation/AMO upload.

Very simple to use and works perfectly.

So cool!
I thank you in (almost) all languages of the world.
شكرا, շնորհակալություն, hvala, gràcies, 谢谢你, hvala, děkuji, takker, hartelijk bedankt, thanks, aitäh, kiitos, kiitti, merci, გმადლობ, გდმადლობთ, ευχαριστώ, धन्यवाद, köszi, takk, makasih, grazie, どうも, អរគុណ, 고마워, paldies, Благодарам, takk, تشکر, dzięki, obrigado, mersi , спасибо, хвала, vďaka, hvala, gracias, tack, ขอบคุณ, teşekkürler, Спасибі, cám ơn, …

:-)

Great. It coud be useful to have a contextual menu with right clic on the search box of the websites to add it more easely to the custom search engine. Have you thought to do it?

THIS IS PERFECT! This is the ONLY thing keeping me from switching to Firefox from Chrome, and I wasn't able to find it a week ago. Now, it is here, and it works just as well as Chrome. I can type my keyword, then hit the spacebar, and suddenly I'm searching in my Google Custom Search Engine.

FANTASTIC WORK, MR SCHUSTER!

GOOD

Seems very useful...
Just a problem (solved by last update: thanks):
With Waterfox , the addon icon is not visible (just an empty square)
In Firefox Quantum, that's fine.