"Miners" and reverse engineering "experts" are still hard at work at trying to figure out all the easter eggs of Pokemon Go
as well as its still unreleased features. After details such as level up rewards and exp required, or even the different kinds of incenses in the game, they have now uncovered what the game calls "Buddy System".
From the information gathered, this Buddy System will allow trainers to have a Pokemon of their choice accompany them over the map as they travel, rewarding them candy specific to the Pokemon chosen and according to the distance walked. If this is true, trainers that were worrying about how to power up legendary Pokemon will be relieved.
While the amount of candy/km has yet to be determined, the miners have found out that there would be a daily limit to how much candy you can earn this way. Regardless, this should be an interesting addition, and I am personally keeping an eye out at the possibility of players seeing each other on the map through a friends system.