It is called Utsushite Honyaku and it is a commercial version service by NTT Docomo which can translate instantly foreign-language restaurant menus when you point a smartphone's camera at them. Right now it is available as a trial version and can handle signs between Japanese and four languages: English, Korean and both simplified and traditional Chinese.
"For example, suppose you visit Korea, and you can't read signs in Korean at all. You can start up this app, select the Korean dictionary, and use it just by pointing your smartphone's camera at the writing you can't read. The translation is shown over the Korean text, so when you use this app, it feels as if you're looking at a sign in Japanese."
"This service doesn't use cloud translation, so instead, the app itself and the dictionary are downloaded to the phone. This means it can be used for free, without having to access the mobile network."