Many Apple users might feel wary of updating their software when a new update is released straight away, for fear of new glitches.
But the latest i Phone, i Pad and i Pod touch software, i OS 10.2.1 out yesterday, is an important one.
Over a dozen security vulnerabilities are described in Apple's i OS 10.2.1 release, including 11 focused around the browser engine behind Safari, the App Store, and lots of i OS apps.
One of the flaws related to the web browser meant clicking on the wrong web content could give hackers access to off-limits areas.
The security flaws also include two cases where applications could take over the device completely.