Too much trouble Rated 2 out of 5 stars
Not working on FF 15 Beta also you have to register on a site to get this working.
Edit:I still have the same opinion.You still have to register on that page and edit a ton of settings.That is way too much trouble for a simple translator tool.
Anyway I found a Userscript which is much user friendlier but I won´t post it here because that would be inappropriate.
Check it out "How to change App ID" article and comment please.