Glass Floor shows you where on the earth is directly below you. Have you ever wondered if you dug a tunnel straight down where would you come out?
Glass Floor takes your current location and shows on a map where the antipodal point to your current location is. You can easily toggle between the antipode location and your current location to get an idea of the separation on the world map. You can also zoom in and out in case your antipode in in the middle of the ocean (as it often is!)