Alkaline is another must-have tweak if you want to customize the look and feel of your jailbroken iPhone. It lets you change your iPhone’s Battery, Wi-Fi, and Data indicators.
For this u have to jailbreak your iOS so for jailbreak see this - http://www.worldshackers.blogspot.in/2015/04/how-to-jailbreak-ios-in-5-minutes.html