iPhone 4
Apple's iPhone 4 is the most popular smartphone in the U.S. REUTERS

If rumors are to be believed the sixth-generation iPhone will arrive in Apple stores worldwide sometime in July 2012, following the iPhone 5, which is struggling for a release date but is expected to arrive in October.

Most of the specifications rumored for iPhone 5 are more or less the same for the iPhone 6. The rumored device is expected to improvise on the 4-inch edge-to-edge screen that is expected to arrive with iPhone 5. The entire front face of the iPhone 6 might fully be screen and, as rumored for iPhone 5, may integrate the physical home button into the display itself.

The iPhone 6 is also expected to be the first device to use the organic radical battery technology developed by Japan's NEC (Nippon Denki Kabushiki Gaisha), which is more environment-friendly than the current lithium ion batteries that have dangerous heavy metals. ORB also boasts a fast recharge time of about 30 seconds and a higher energy density that will pack more power into a smaller battery.

The other widely rumored feature is the iPhone 6 camera, which is expected to be the first iPhone to arrive with a 10 MP camera with high-definition image output. 64GB and 128GB memory variants are also expected to be available with Apple working on phone storage options.

Previously a Japanese newspaper, Nikkan, had reported that the upcoming iPhone 6 will use a new display material that will make it thinner, lighter, and less power-intensive than current displays and may mean saving a great deal of battery life. The screens are expected to be of Gorilla Glass make coupled with p-Si touchscreen that will resist breakage and make it the toughest-screen iPhone ever.

The Livelonger Hubpages predicted that although there are very less chances of a NFC (near field communication) based iPhone 5 at the moment, the iPhone 6 will definitely be embedded with NFC capabilities that will make contactless communication easier.

Other rumored features include a "pico-projector" that will enable a video to be projected at a short distance onto a flat surface, face and thumb recognition features, and even a transparent phone.