Niantic added the new Buddy System in the latest Pokemon GO update, but there’s a little detail in the patch notes you might have missed out on. As stated on their official webpage, it seems that this update will also cause the app to cease support for rooted Android phones and jailbroken iOS devices.
‘We continue to focus on eliminating bots and scrapers from Pokémon GO. Rooted or jailbroken devices are not supported by Pokémon GO. Remember to download Pokémon GO from the official Google Play Store or iTunes App Store only.’
This was likely done to eliminate the problem of players cheating by using GPS or location spoofing tactics. However, this method does seem a little heavy-handed. It’s pretty common for Android users, in particular, to root their phones so that they have more options when it comes to customizing their devices. While it is likely that most cheaters will come from the subset of users who crack their devices, this method might end up affecting other ‘innocent’ users as well.