Button4Phone is a tweak available since last evening in Cydia, and with its help we can modify the button that allows us to call phone numbers using the Phone application. Normally the button is rectangular in the Phone a application iOS 7, but after installing this tweak we will have a circular button completed by two more buttons on its edges. The tweak has been tested so far only on 4-inch screens, so it is not known if you will be able to use it without problems on 3.5-inch screens.
For ios7. make the call button round. add two buttons beside it 4 inch iphone is ok, 3.5 not sure.
Button4Phone it is available for free in the repo BigBoss al Cydia.
