With rumours heating up that Apple will announce an iPhone 6 by year-end, concept designers are working their fingers to the bone and YouTube is lighting up with their videos. 

The latest attention-getting concept design video comes from Sam Beckett, a British graphic designer who The Huffington Post says has a strong track record when it comes to predicting features in new iPhones, as he did with the iPhone 5 and iOS 7.

Bigger iPhone Air preview

In his video, Beckett portrays a smartphone that is 8% larger than the current high-end iPhone 5S and boasts a 4.7-inch screen with 1920x1080 pixel resolution. At 7mm thin, the concept phone is 0.6mm slimmer than the 5S. The phone's exterior shimmers with a sapphire crystal display, replacing the old Gorilla Glass, and ups the camera from 8mp to 10mp. One other nice detail: Beckett includes on the screen the Healthbook app Apple is said to be working on.

Beckett suggests Apple will stop naming its iPhones by number and shift to the iPhone Air moniker, along the lines of what it's done for its Macs and iPad tablets.

One reason Apple watchers like this concept design (it's "amazing," exclaims one) is that it isn't too out there. 9-to-5 Mac, for example, says: "There are a lot of very silly iPhone 6 concept images and videos around, from convext curves that maximize reflections and vulnerability to damage, to completely transparent phones (invisible batteries and circuit boards are the new black, apparently). This concept by Sam Beckett isn't terribly exciting, but it is likely reasonably close to what we might expect Apple to do ..."

Hopes are high for the next iPhone: Crazy big numbers are being bandied about in the rumor mill, with some even suggesting 90 million iPhone 6 (er, iPhone Air) smartphones could be ordered this year. 

(See also: The 10 weirdest Apple concept art designs.)