iOS devices have a slide switch near the the volume up and down buttons that can be set to behave as a mute button or for locking the screen rotation. Please check these settings and also ensure the volume is turned up. A simple test is to plug in some headphones and test the volume. Version 1.0.3 provides an option to override the device sound settings. You really need this to keep your computer and documents from being damaged by viruses. Once installed, make sure the anti-virus software is set to update and check your computer automatically.
If you’re using an old version of iOS on a device,