Fair disclosure: I'm an Android user, and I'm not sure what Japan Goggles is.

But on my recent trip to Tokyo, I found the free (for Android) Google Goggles to be very useful in translating Japanese text. To be sure, it failed about as often as it succeeded, but even a 50% success rate is better than I could manage with my limited knowledge of Japanese, so I was quite happy.

If Google offers something similar for iPhone, I would expect that it would be just as effective and hopefully also free.