'Photo Blackground' Makes the Background Behind Photos Black Instead of White in iOS 7
One of the annoying aspects of iOS 7 is how the Photos application now puts a bright, eye-jarring white background behind the photograps in your Camera Roll while the navigation bar is showing. The bright white draws the eyes away from the photograph and makes it more difficult to focus on. If you hide the navigation bar at the top in iOS 7, the background changes from white to black, making the transition even more unbearable on the eyes.
A new free jailbreak tweak dubbed Photo Blackground
by iOS developer Harlan Haskins changes this, by making the background behind the photograph black instead of white when the navigation bar is showing, as shown above.
Not only does this make it so that the background behind the photograph is black whether the navigation bar is showing or not, but also the black background is a much better color to have behind the photograph because it's easier on our eyes, so the tweak improves visibility.
If you want to give tweak a try, it's available in Cydia's BigBoss repository for free. The tweak has no options to configure.