Apple iPhone 4

Released in June of 2010, the Apple iPhone 4 is the successor to the iPhone 3GS. It is the fourth generation iPhone that builds and improves on the features of its predecessors and adds a few of its own.
Perhaps the most obvious improvement on the previous iPhone is the stainless steel frame that has not been insulated so that it can act as an antenna. The display has also been vastly improved, from the 480 x 320 resolution of the 3GS to 960 x 640 in the iPhone 4, resulting in extremely clear, crisp, and distinct images. It is a 3.5-inch LED-backlit capacitive touchscreen with a surface that resists scratches and oil.
One of the main features of the smart phone is its FaceTime technology. This consists of an embedded video calling application that can use either of the phone’s two cameras to allow callers to see each other as they talk provided at least one is using an iPhone 4 and the other is also using another iPhone 4, fourth generation iPod Touch, or any Mac computer with a Mac OS X 10.6 Snow Leopard.
The primary camera of the smart phone is a 5-megapixel camera that is supported by an LED flash. It is mounted on the upper right corner of the back of the phone, with the flash immediately beside it. Apart from taking still photos, the camera can also record videos in resolutions of HD 720p at 30 fps. If you want to edit your videos, you don’t have to wait to get to your laptop. You can do it right on the phone. The secondary camera, a VGA camera, is mounted in front, above the display. It is primarily designed to record your image when using FaceTime.
The iPhone 4 also takes multitasking to higher levels, allowing you to run third-party apps without affecting the speed of the foreground app. Switching between them is also quick, requiring you only to double-click the home button to retrieve your recently used apps, and to tap the one you want to open. If you do not see the app you want, simply scroll to the right by running your finger from the right side of the screen to the left.
The unlocked version of iPhone 4 supports GSM 850/900/1800/1900 as well as HSDPA 850/900/1900/2100.