I downloaded Google Translate and Waygo, a translation app that got some decent reviews on various travel sites. Neither were accurate, but I tossed Waygo after the first few days.
This was Waygo's translation of a Japanese sweet:
Both apps worked the same way. Open the app, position your phone over the text and click the little camera icon. "Live" translation appears on the screen, and I use the word "live" purposely - the translation changes as you move the camera around, and is, overall, not especially accurate.
If you are connected via wifi or cell, you can click the camera icon and a shot of the text is sent...somewhere. And you get a much more accurate translation. Here's part of a receipt:
Here's the "live" Google Translate:
And here is the final translation:
Useful? Kinda? But, hey it's free.