Apple issues an update to the software that powers its iPhone, iPad, and iPod Touch devices once a year, and this years update is finally upon us in the form of iOS 8. You should routinely update your software and devices for security reasons above all else, but if youre putting off the iOS 8 upgrade, here are a few compelling reasons to download it immediately. Track Your Health HealthKit is the name of the API used by developers to collect and manage information about an iPhone users movement.