While previously stated as a rumor, Pokemon GO will be receive a new update that will allow people walk with their preferred Pokemons. Doing so will unlock various features such as candies!
The next addition to Pokémon GO will be Buddy Pokémon. You will be able to pick your favorite Pokémon from your collection to become your buddy, opening up unique in-game rewards and experiences. Buddy Pokémon will appear alongside your Trainer avatar on your profile screen, adding helpful bonuses such as awarding Candy for walking together. You’ll also have the ability to change your Buddy Pokémon at any time.
I can already imagine how much easier this will make it feel when evolving certain Pokemon not to mention saving up on those Pokeballs. No ETA has been given yet but expect it to arrive soon.