Let's face it: Apple's current iPhone 6 and 6 Plus flagship took the market by storm, recording four million preorders in the first 24 hours of their official release. Of course, the number has increased over time -- but with the iPhone 6S and iPhone 7 churning rumor mills at the moment, we can only predict iPhone 6's sustained success.

Stabley Times claimed that the iPhone 6S may arrive alongside the Apple Watch in Spring next year. If this holds true, the device might also be meeting the rumored iPod touch 6G and iOS 8.2 update, as reported by Customs Today.

As for the iPhone 7, Stabley Times noted that it could opt for a September 2015 release. That gives the handset approximately a six-month gap from the 6S.

However, Customs Today mentioned in another report that Apple could finally ditch the idea of an iPhone 6S -- and head straight to the release of a new iPhone number. According to the outlet, the iPhone 7 and iPod touch 6G's release may happen simultaneously.

Daily Mail reviewed Apple's traditional release pattern, when the Cupertino giant maintained a single iPhone launch annually until 2013. Last year saw the arrival of the iPhone 5S and the funky-colored iPhone 5C. This year, we welcomed the birth of iPhone 6 and the larger iPhone 6 Plus.

Is 2015 giving us the iPhone 6S and iPhone 7?

Nevertheless, here are the most notable of iPhone 6S rumored specs and features to date.

A9 Processor. BGR cited in an earlier report that these processors are expected to run Apple's 2015 iPhone model. Accordingly, volume production of these chips takes place in the first quarter of 2015. The outlet referred to the rumored model as the iPhone 6S.

DSLR-Quality Photography. This speculation was born from John Gruber who told Daring Fireball, "The specific thing I heard is that next year's camera might be the biggest camera jump ever. I don't even know what sense this makes, but I've heard that it's some kind of weird two-lens system where the back camera uses two lenses and it somehow takes it up into DSLR quality imagery."

Sapphire Display. According to MacRumors, Focus Taiwan cited a report from China Economic Weekly which claimed that Foxconn Technology Group has built a new factory close to a Zhengzhou-based iPhone 6 assembly plant. This facility was reported to be the site of sapphire display production for Apple's future devices. It must be noted that no particular iDevice has been named; therefore, we cannot rule out its possibility for the iPhone 6S.

What do you want to see in the next iPhone flagship? Comment below.

Watch M Eliasson's concept of the iPhone 7.