iOS 4 for Apple iPhone 3GS is to be released on June 21. We have found that the iOS 4 Release Time will be around 9:00 AM Pacific. This iOS 4 update is very significant to a lot of users for the Multi-Task feature that comes with this version of the iPhone Software. In previous years we have seen Apple have download problems thanks to heavy demand, with iTunes errors, and server connection problems. The latest iPhone 4 will already have the new iOS 4 installed, and this seems to be the most pain free way of getting the latest iPhone OS.
The user interface of iOS is based on the concept of direct manipulation, using multi-touch gestures. Interface control elements consist of sliders, switches, and buttons. The response to user input is immediate and provides a fluid interface. Interaction with the OS includes gestures such as swiping, tapping, pinching, and reverse pinching. Internal accelerometers are used by some applications to respond to shaking the device or rotating it in three dimensions.