Hello!
How will the app detect the coins in a place? - you install the app, open it and see the map with tokens on it. App finds your location and shows you tokens in your area. You become hunting them and when you get as closer as you can, the camera of your smartphone becomes active and you will see the token right in front of you - profit!
Do the coins exist everywhere like no resticted country? - Of course. Tokens can be placed everywhere in the world - it depends on where the app was installed. It's augmented reality - we don't have geographical boundaries.
Is the app already running? (I've heard about an app similar to IZETEX a couple of years ago from a friend. I don't know exactly what the name is) - Sure and it has about 43.5 k. users all over the world - join