Google translate app works pretty well for translating Kanji.
Free WiFi is fairly prevalent. Particularly is you use the Japan Wi-Fi app and register online before you go. Given that many of the pocket WiFis throttle your speed after a certain amount of data, I hae tended to switch between the two.
I use the Tokyo + Rail Map app to help work out metro routes. It's not always perfect (as you get more familiar, you may figure out a "better" route for you, but it is at least a good start
My 2 cents