Per Pokeminers Toronto, the game's code had hints of subscription-like services in the past, but they've not yet been implemented in the live game. The most recent update to Pokemon GO included ...

A new Pokémon GO datamine has discovered Ash Greninja, Primal Groudon, Primal Kyogre, and the Formes of Keldeo, Shaymin, Necrozma, & more.

Pokemon Go trainers have a shot at catching Tornadus, Thundurus, and Landorus with this Timed Research, but it won't be easy.

Pokemon GO regularly comes with Redeem Codes that provide access to in-game elements. There are Offer Codes and Promotional Codes that you can Redeem for the returns.