Update: iOS 8.4 has been released, and so is TaiG 2.3 jailbreak for iOS 8.4. iPhone 6, 6 Plus, 5s, 5c, 5, 4s, all iPads and iPod touch 5 are supported. You can download it from below and then follow our guides on how to jailbreak your device on iOS 8.4 Cydia.