wiktionary filter — akasen

For example, when you set the language to Spanish and access to https://en.wiktionary.org/wiki/ser, you will be redirected to https://en.wiktionary.org/wiki/ser#Spanish.
When the hash is already set, no redirection occurs.

And it has a search box of en.wiktionary.org at the top.

NOTE:
This addon is developed with the English version of wiktionary in mind. Its functionality is pretty simple, so it will work in the other language versions of wiktionary, but any language other than English is not currently supported.