However, it seems that Niantic does not like the idea of custom recoveries existing on the phones of players who are playing Pokemon GO because in a recent update to the game, it has been discovered that players who might have custom recoveries on their phones are being blocked in the game.
Basically, it appears that the update will check the player’s phone for folders named “TWRP” or “Fox”, both of which are related to custom recoveries. As Android Police notes, it seems that the game could actually be exploiting a bug in Android that allows for it to check for directories without it being granted storage permission.
We imagine that the reason for this block is because Niantic is hoping to cut down on the number of cheaters in the game, although this might be unfair to players who aren’t cheating and are using custom recoveries for their own uses. It is unclear if this might be a mistake, but if you do have an Android phone that has custom recoveries, then you might want to take this into consideration.