If you are an iphone user, you might have seen that when ever you need to note something while you are on call, or just in case when you run an app while making a call, you will see the green status bar tapping on which resume you to call screen dialer with all call options.
BusyBar, a free iPhone tweak available in Cydia, lets you apply that same status bar effect with any app you’d like. BusyBar lets you invoke a similar bar, close your app, do as you like, then tap to go right back to that app immediately, just like the green in-call status bar that Phone call app, except it’s red in color as you can see in the image below.
It allows you to use activator to active the in-cal status bar, then exit any certain app, and do as you please. Then Tap the Bar to go back to the call immediately. It requires IOS 4 or Higher and its Free to install and use.