Essentially, it means that, without having to launch the game, you’ll still get your real world adventures recorded and applied to the game. This means that mechanics that rely on them, like accumulating candies and hatching eggs, will get a passive boost. You’ll also save on battery life for your phone since you don’t have to have the app on.
Adventure Sync will begin to roll out soon, but Niantic stopped short of saying when exactly. The company also says that it’s a feature that will be added to its other titles, Ingress and Harry Potter Wizards Unite. Once the new feature arrives, it will be as good a time as any to get into Pokémon Go. The game just added Generation 4 Pokémon, and with Adventure Sync, your phone will actually last long enough for you to enjoy every addition to its fullest. (Source: Niantic)