Answer to: The volume bar has disappeared. There's no sound in apps.If your speakers are working, and the only problem you have is that the volume bar is gone, you might just need to clean your dock connector. Turn off the device and then gently brush the dock connector using an old toothbrush. You can't imagine how much dust you can find down there. Sometimes this can cause the iPhone to act as if it is docked to an external speaker, canceling the volume controls on the device. Good luck!