The rumour mill of iPhone 6 and iPhone 5S is composed of a wide array of speculated features. However, it is still unclear which features will materialize in the rumoured device.

Moreover, there is no clear date yet as to when the highly-anticipated Apple's smartphones will hit the shelves. It seems that the rumoured imminent release date of iPhone 6 and iPhone 5S will not happen as previous iPhone models remain expensive.

Listings on the online retail giant Amazon, iPhone 5 is still being sold between $700 and $900. iPhone 4S costs around $500. iPhone 5 under a contract bears a price tag that ranges from $99 to $199.

The rumour is fuelled by the speculation that the release iPhone 6 and iPhone 5S will be postponed due to US carrier T-Mobile's delayed availability of the current iPhone. It has been less than a week since T-Mobile announced the long-awaited release of the iPhone 5 on its network free of contract. The smartphone will make its debut with T-Mobile on April 12. Pre-orders for the handset began for the iPhone 5 on Friday.

With the delayed availability of the handset in T-Mobile, Apple may not release the successors of the handset yet. Rumours claimed that Apple is set to unleash iPhone 6 and iPhone 5S in June.

Some of the rumoured features of the next iPhone are Retina or IGZO screen display, A7 quad core chip processor, iOS 7, 128GB internal storage, 13 mega-pixel camera, and longer battery life. The lack of NFC support on the iPhone 5 was one of the biggest criticisms aimed at Apple's smartphone.

The low cost iPhone 5S, on the other hand, is rumoured to sport a plastic casing, 4-inch screen display, dual core processor and 8-megapixel camera.

As usual, Apple did not comment on the rumours about iPhone 6 or iPhone 5S.

Below are some of the killer features of the upcoming iPhone 6 and iPhone 5S that will surely make it ace the competition.

  1. Near Field Communication - One of the biggest insults on Apple's iPhone 5 is that it did not support NFC transactions. In order to keep up with the market, the company will surely include this feature.
  2. Longer Battery Life - One of the usual complaints of iPhone users is the fast-depleting battery. Apple should improve the battery life of the handsets in order to keep up with the competition.
  3. IGZO Screen Display - One of the popular rumours on the iPhone 6 is that it will include Sharp's IGZO screen display.
  4. 128GB Internal Storage - Apple already included a massive storage in its latest version of iPad. Consumers will be attracted to the big amount of saving space in their handsets.
  5. A7 Processor - Some people want speed, especially when they are doing something important in their handsets. Thus, the rumoured quad core A7 processor is a must for the next iPhone.
  6. iOS 7 - An updated operating system that greatly supports all of the functions of the handsets is needed.
  7. Different Screen Sizes and Color Options - One of the rumoured designs of the iPhone 6 and iPhone 5S is that it will come in two sizes and various colors.
  8. Enhanced Indoor Mapping Technology - Apple is working on its troubled iMaps. The iPhone maker recently bought the location-based service firm WifiSLAM to bring indoor mapping technology to the company.
  9. BBM-Like Instant Messaging - Apple was granted a patent for its invention relating to portable electronic devices, and more particularly, to portable devices for performing instant messaging.
  10. Eye Protection - Apple developed a technology that will avoid Luminescence Shock, which is the sudden visual impairment brought by bright screen displays in a very dark environment. The technology will limit the brightness of the device when activated in dark environment.