>This function is a map of Sinnoh saying where you are. It allows you to put placemarks at certain areas so that you can maybe know where you're going if you get lost. Also for the two Pokémon that run, Mesprit and Cresselia, they show up on this Map so you know where they are
Location: Obtained from President of Poketch Company after obtaining 3rd Badge
The Poketech is in the large building (not tall, but wide) in Jubilife City. There is this man standing by the counter.
Hope I helped!