Terrarium should support geofencing so that when you enter/exit a new area a status could optionally appear with the place name. This could be done through toasts or the status bar.

You'd basically have to write collision for each geographical area, possibly with a bit of overlap where you just keep the last location you were in so you don't get spammed with "Welcome to Texas, USA" "Welcome to <place>, Mexico" over and over by walking along the border.