Fans of Doctor Who will enjoy the simple, yet elegant WinterBoard theme Gallifreyan Keypad. This free theme from developer Puka1701 converts the lock screen keypad numbers into Circular Gallifreyan glyphs. Glyphs also appear in the Phone dialer, but only when numbers are pressed.
The theme integrates perfectly with iOS 7, which is required for installation. Gallifreyan Keypad is dependent on WinterBoard and only works on the iPhone and iPod touch. Once installed from Cydia, the theme can be enabled under Settings -> WinterBoard -> Gallifreyan Keypad on a jailbroken device.
For those who might be wondering, the question mark in the status bar is not part of the theme. This touch was added with the jailbreak tweak Zeppelin, which has recently been updated for iOS 7. Carrier name can be changed from Settings -> Zeppelin -> Carrier Text.Gallifreyan Keypad is available on Cydia from the ModMyi repo for free. Check here for instructions on how to jailbreak iOS 7.x with evasi0n 7. You can also find out how to purchase and install Cydia tweaks with this guide.