The search is somehow worse than Google

Also, Firefox has a thing called Search Shortcuts, which lets you use keywords (like @google) to search using a certain search engine, deleting the word from the URL bar in the process. For some reason, this can't be turned off and you can't change/remove the default keywords.
With this extension, the keyword is just "yahoo". So you can't begin a search with the word "yahoo".

Why?

Please add this extension for mobile browsers!

Es imposible configurarla en español

nice app that really helps.

Not a good search engine. Please fix this!

It does not seem to work any more; search pages give the message "The page isn't redirecting properly".

I like it

Excellent