This app was mentioned in 6 comments, with an average of 2.00 upvotes
Hyperdia is great on Android. But it's really not so complicated, OP was looking for the Yamanote line, if he just followed the giant green signs that all said Yamanote he'd be fine
I know for sure I haven't paid a single time for it, although I have considered doing so in the past. I wonder if it's a peculiarity of the iOS version, for Android (which is what I use) there's not even a mention of this time limit on https://play.google.com/store/apps/details?id=com.hyperdia.android.activity
EDIT: From a cursory glance at the terms of service of the Android version, it looks like there's no explicit mention (although Article 3 of the agreement mentions something similar without going in the details).
No, that's a different app. This is the one for Android:
https://play.google.com/store/apps/details?id=com.hyperdia.android.activity&hl=en
And this should be the one for iOS, but I don't use iOS:
https://itunes.apple.com/us/app/hyperdia-by-voice/id379001449?mt=8
For train schedules these look promising. https://play.google.com/store/apps/details?id=com.hyperdia.android.activity
https://play.google.com/store/apps/details?id=com.navitime.inbound.walk
I usually use HyperDia.
Here is a post from a couple weeks ago with a bunch of information. Top comment goes into a TON of detail about setting up your phone for your trip. It talks about OSMAnd and MAPS.ME. Personally, I used Google Maps (with T-mobile's free 2G data) exclusively and it worked very well, save for the rare time I could not get good cell signal.
It's also a good idea to install Hyperdia, which will help in planning train rides with exact costs, although you need to know the name of the stations you're traveling between. Lastly, while I didn't use it much, Japan Rail Map displays rail lines nicely and also shows wifi hotspots.
Oh, also, I know it isn't about maps, but unless you speak good Japanese make sure you download both English and Japanese in Google Translate so you can use them offline! Helped me out a LOT.