Niantic Labs has recently rolled out the highly-anticipated Pokemon GO Gen 2 update with access to over 80 new Pokemon characters, which can now be evolved into five different forms of Eevee including the new Espeon (Psychic type) and Umbreon (Dark type). Prior to the Gen 2 update, Eevee was already capable of transforming into Flareon (Fire type), Jolteon (Electric type) and Vaporean (Water type).
Veteran Pokemon GO players have discovered new ways to limit evolution of Eevee to a particular type by renaming it with a specific name from the Pokemon anime series. For instance, renaming Eevee as 'Pyro' would ensure its evolution into Flareon, and you get Vaporeon when you rename it as 'Rainer'.
Similarly, it is now possible to rename Eevee as 'Sakura' and 'Tamao' to ensure its evolution into Espeon and Umbreon respectively. Those who are yet upgrade to the latest version of POkemon GO may go ahead and install Pokemon GO v1.27.2 for iOS as well as Pokemon GO v0.57.2 for Android, using the download links provided below:
Pokemon GO 0.57.2 for Android or APK file here
Also, check out our step-by-step guide to install Pokemon GO++ GPS aka location hack 1.27.2/0.57.2 for iOS and Android.