An interesting app that i did not get a chance to use yet is Google Translate. This app allows you to speak and it will translate to text. There is also the option to draw out the Japanese characters if you don't know how to use the Japanese keyboard in your phone.

https://itunes.apple.com/us/app/google-translate/id414706506?mt=8
https://play.google.com/store/apps/details?id=com.google.android.apps.translate&hl=en