..... I dont know what your talking about but i think you mean a pokedex, but really you just go into some grass!
You dont
you talk to the Pokemon watch president and he will give you apps and one of them is the tracker app
you can find legendary Pokemon by using your Pokemon tracker
from the pokech guy
it doesnt exist in Pokemon
Simple buy the game new in the collector package
Beat the game, complete the Pokedex, then talk to the Pokemon Prof.
you have to get the national dex. u have to see everything on the sinnoh dex.
use a poke tracker on watch
Its not Azelf its Mesprit that flees and you get it by using the Pokemon tracker app and you wil need a Pokemon with mean look so Mesprit does not flee.
ok if your talking about a shiny in Pokemon pearl/diamond an easy way is to use the poke tracker and if you see a sparkle in the grass its a shiny.
if your talking about a Pokemon radar after u get the national pokedex installed the professor will give you it. but if ur talking about the marking map which can show where the wild Pokemon that fled from battle like a cresselia its already been install on the poke watch