verified to work: iOS 2.2 through 6.1
Let's face it, the iPhone isn't really a "phone": to call someone you have to:
1) turn it on 2) unlock it 3) exit Safari ;P
4) find the Phone app 5) click the icon
6) find contact 7) call. Frowny pants.
With CyDialer, we have a phone again:
1) turn it on 2) find contact 3) call.
Put simply: all of your Phone favorites are displayed in a fast coverflow of photographs, right on your lock screen.
Note: CyDialer only supports "normal phone calls", not Facetime records.
CyDialer isn't really anything "new": others have made similar extensions, both for the iPhone and other devices.
What sets CyDialer apart, however, is its attention to detail and quality. The interface has been designed to blend smoothly into the existing lock screen experience with calculated usage of fade effects and animated transitions.
For users of the built-in keypad lock feature, CyDialer integrates with the mechanism one would expect, sliding the interface in and out seamlessly.
Careful attention has been made to issues of "pocket calling": tapping a contact does not immediately initiate a call until the user "slides to call"
Like Cyntact (a perfect compliment), CyDialer is a well tested extension that is designed to be easily maintained as Apple releases new firmware updates.
As my friends and I have been using it on our phones now for years, this extension has already been well tested and debugged in many environments.
CyDialer is an "away view plugin", making it play nice with all of Apple's existing lock screen extensions, and is managed by Cydget. To activate it, you will need to go under Cydget Settings.