'HBUC' Hides the Numeric Battery Percentage Until You Plug it Into a Power Source
Many of us prefer to have the battery percentage show in the Status Bar alongside the battery level icon, but instead of having it show all the time, a new free jailbreak tweak called HBUC
(short for Hide Battery Until Charged) by iOS developer Aaron Thomas is now available that will only display the numeric battery percentage when the device is actually charging.
With the tweak installed, if you're not charging the iOS device, it'll still show the battery icon, but the numeric battery percentage indicator will only appear when the device is connected to a power source:
Since we want to be 100% sure that the indicator actually says 100% before we unplug it from the power source (it's an OCD quality many of us have), it makes a lot of sense to have the additional information when we're charging our device. But for the most part, when we're using it day to day, all we really need to see is the battery indicator icon to have a rough estimate of the battery level.
If you would like to give HBUC a try, it's available for free in Cydia's BigBoss repository. It doesn't have any options to configure.
iPhone 5 running iOS 7.0.6