After a false start earlier this morning with an update to its iOS 8.4 jailbreak tool, TaiG has officially released version 2.2.1.
This update is security oriented, as it contains the setreuid patch to prevent applications from obtaining to root privileges through setreuid. The update also contains stability improvements. If you've yet to jailbreak your iOS 8.4 device, it is recommended that you use this latest version of TaiG's tool, version 2.2.1.