IPhone 4

Background Information
The iPhone 4 much like older models of the iPhone is a smartphone with key features including a native mailing app, a web browser, SMS messages, a phone function, and an iPod among other things. The iPhone 4 comes in black and the long-fabled and newly released white color much like the iPad 2. The iPhone currently runs iOS 4.33 and was shipped with iOS 4. The iPhone 4is available in 16gb and 32gb models from Apple. You can also buy it carrier unlocked from apple's website The device can also be bought from AT&T and Verizon the two U.S carriers who carry the phone.

FaceTime
The iPhone 4 adds a new feature to the iPhone line, FaceTime. FaceTime allows a user to make a video call over Wi-Fi connection to another iPhone 4, fourth-generation iPod Touch, a Mac running Snow Leopard, or an iPad 2.

Camera & Photos
The iPhone 4 features two cameras, a front facing VGA camera, and a 5 megapixel rear-facing camera. The rear-facing camera can shoot video in 720p.

Retina Display
The display on the iPhone 4 is designed by Apple and manufactured by LG. It features a multi-touchscreen with pixel density of 326 pixels per inch (ppi). The screen is marketed as a "Retina Display", based that 300 ppi at 12 inches from the eye is the maximum amount of detail the human retina can process.

Death Grip
Due to the placement of the antenna in the iPhone 4, users were experiencing a loss-of-signal when gripping the iPhone 4. Apple discovered the cause of the "dramatic drop in bars" was due to the formula they used to calculate signal strength. In an update to iOS, they fixed the formula. On July 16, 2010, Steve Jobs announced Apple would provide a free case to all iPhone 4 customers to increase signal strength. This was said to be corrected with the release of the CDMA iPhone 4, now available on Verizon.

Bumper
An iPhone 4 Bumper is a ring of rubber that surrounds the edge of the iPhone 4. The Bumper is designed to strengthen the signal of the iPhone 4. Different bumpers had to be manufactured to accomidate the CDMA version of the phone

Carriers
The iPhone 4 was originally released excessively to AT&T in the U.S. On January 11, 2011, Verizon announced they will be selling a CDMA version of the iPhone 4. They have added a 'Mobile Hotspot' feature allowing users to use the iPhone as a wireless hotspot for up to 5 connected devices. They also added a new camera which they hope to solve the 'Death Grip' problem.