I actually used it for my Zmanim App - https://play.google.com/store/apps/details?id=com.wyre.zmani...

This app provides jewish prayer times. I use these apis to get the users precise current location so that we can tell them the prayer times even while flying in a super accurate way.

Fun fact: I hooked into the captain announcements SSE feed and a popup shows up that blocks users from using the app while the captain is talking.