Pokédex 3D Pro is a paid download for the Nintendo 3DS eShop. This download follows on from the free download of Pokédex 3D and features all of the Pokémon to exist.
While the game features all Pokémon, it contains data for Pokémon Black 2 & White 2, showcasing the Pokémon in 3D and providing moveset data for all. It also has Augmented Reality features. It also has a special Pokémon Challenge mode as well as an album for all your screenshots in the AR Viewer
Unlike the previous game, you will receive all the Pokémon immediately out of the box, without the need to use the system's SpotPass feature to obtain 3 each day. This includes all forms counting up to 727 different entries within the Pokédex. This does not include Genesect or Meloetta
The Pokémon Challenge aspect provides a variety of quizzes of varying difficulty to test Pokémon knowledge. These range from identifying Pokémon by appearance, by moves, by stats and even by their cry
While the game only has Bulbasaur to Keldeo within it when you begin, you have the ability to access Meloetta, and presumably Genesect at a later point, via a password added in Pokémon Challenge