(Note that this is experimental and is subject to change. Also if the Pokemon is already captured it'll need to be recaptured after evolving it.)

First thing that needs done is go gather "x" amount of xp and drop it on (PokemonNameHere) and wait a couple of seconds and it will evolve.


XP amounts:

Caterpie -> Metpod : 400 xp
Bulbasaur -> Ivysaur : 1600 xp
Ivysaur -> Venusaur : 3200 xp

Stones:

Eevee -> Flareon : Firestone
Eevee -> Jolteon : Thunderstone