firefox addon which allows you to type Japanese characters?

Hey, on my old computer i used to have an add-on to firefox which enabled me to press F2 and write in hiragana and katakana

I cant remember what the name of the addon is, and need it for my studies! :(

I think it also let you type in other foreign characters on settings

Does anyone know what its called? It was a free addon i found on the Firefox website

Thanks!