Some have experienced their alarms not going off, apps closing unexpectedly.
The update will "make everyday tasks on iPhone and iPad faster and more responsive," Apple said.
Group FaceTime calls, faster performance and improved AR sound good, but what's the catch?
"When every moment counts, these tools will help first responders reach our customers when they most need assistance."
Android users have enjoyed grouped notifications for a while now.
The Apple CEO responded to fears that taxes imposed on China could have a knock-on effect on U.S. tech companies.