Intriguing new concepts envision the next-generation Apple smartphone, presumably called the iPhone 6s or iPhone 7, and the improvements it could boast.

Apple has seen great success with its iPhones so far, and each new iteration stirred more interest and gained more fans. While Android fans argue that iPhones are far behind rivals in terms of specs and features, Apple is expected to introduce some notable improvements with its next-generation iPhone.

Unofficially dubbed the iPhone 6s or iPhone 7, the next smartphone from Apple is expected to make in September 2015, as per Apple's usual product cycle. The iPhone 6s/7 will run iOS 9, with a slew of features and treats aiming to deliver a stable and high-quality experience. Apple should preview iOS 9 at its upcoming WWDC 2015, which kicks off on Monday, June 8.

The 2015 iPhone is rumored to add a number of upgrades compared to its predecessors in terms of hardware specs as well, including a full HD (1920 x 1080 pixels) display for the 4.7-inch model and a high-resolution 2K (2560 x 1440 pixels) panel for the 5.5-inch phablet.

The next-generation iPhones are further anticipated to rock a powerful new Apple A9 processor, more RAM, advanced software features, and the Force Touch technology found on the new MacBook and Apple Watch. The iPhone 6s, or iPhone 7, is also expected to boast upgrades in the camera department, rocking a 12-megapixel rear shooter with Sony's RGBW pixel technology.

Design-wise, Apple will likely retain the same design language and form factor of the current iPhone 6, except for the rear camera module.

None of these rumored specs are confirmed at this point, and we're still several months away from the September unveiling of the new iPhones. Nevertheless, some intriguing concepts now paint a picture of what could be on the table, showing the potential of the next-generation iPhones.

Popular designer Jermaine Smit created a number of concept designs to show the potential of the iPhone 6s/7. Smit imagined the iPhone 7 with a 12-megapixel rear camera, a 4-megapixel wide-angle lens front shooter, 2GB of RAM, and more. The specs are simply conceptual and don't depict actual products or confirmed plans, so treat them accordingly. Check out the envisioned upgrades in the concept video shown (via Phone Arena).