Swipe to Return Missed Calls From iPhone Lock Screen
Miss a phone call? Rather than tapping through to the recent call log and finding the last caller, you can immediately return a missed call by swiping to the right on the phone icon alongside the callers name, directly from the iPhone lock screen.
You’ll need iOS 5 or later and Notifications Center must be configured to include phone alerts to do this. The feature should be enabled by default, but if it’s not and you want to turn it on, tap to Settings > Notifications > Phone and make sure Notification Center is turned ON and alert style is set to “Alerts” or “Banners”.
Thanks for the tip Laurence