If you updated your iPhone 6 or iPhone 6 Plus to iOS 8.0.1 you may be experiencing cellular service or Touch ID issues. Here's the instructions on how to downgrade back to iOS 8.0.
MuscleNerd has announced a major update to RedSn0w that removes the need to select an IPSW and brings the ability to save and submit your SHSH Blobs to Cydia.