Previewing Apple's WWDC 2016: Big news for iOS 10, iPhone 7, new iPad Pro

Rumors of iPhone 7 have so far revolved around purportedly leaked schematics and part images, which only allude to obvious potential hardware changes (a dual lens camera, an iPad Pro-like Smart Connector and replacing the legacy headphone jack with Lightning). However, many of Apple's biggest iPhone leaps have been externally invisible, driven by software advances unlocking the power of advanced silicon hardware inside, many of which debuted at WWDC.

Apple's Swift invite to WWDC 2016

Apple is notoriously secretive about its future plans right up to the point where it is ready to release new hardware at its Apple Event launches, or alternatively, new software and cloud services at its annual Worldwide Developer's Conference in June. Here's what to look forward to at next month's developer event, focusing specifically on iOS 10 and the devices that run it.

WWDC is all about software, as it is the company's annual meeting with app developers, accessory partners and others who interface with Apple's platform APIs. While the company has occasionally debuted new hardware at WWDC, in recent years the event has focused almost entirely on new software releases (iOS, Mac OS, watchOS and iCloud) and ways developers can make the most of Apple's platforms.WWDC has showcased incremental advancements that provide clues about where Apple is headed

Apple's WWDC has showcased incremental advancements that provide clues about where Apple is headed—including strong foreshadowing of future hardware. 

For example, Apple began talking to developers at WWDC about gaming related hardware controllers long before it introduced Apple TV. It also unveiled its Bluetooth-based Continuity services prior to introducing Apple Watch, which tightly integrates with your iPhone using those same technologies first perfected on Macs and iOS devices. Last year's iPad multitasking features in iOS 9 were a harbinger of the two new upscale iPad Pro models aimed at business users. 

Previous iPhone innovations were often invisible to spy shots

Consider first how little we knew about earlier iPhone releases just from spy photos circulated before their launch. Apple's second generation iPhone 3G debuted a cheaper plastic case than the original model, intended to make it affordable to a much larger audience. But inside that shell was a series of major improvements ranging from its application processor chip to its camera and support for 3G mobility and GPS location services. A spy photo would not have revealed any of that.

The next year, iPhone 3GS looked virtually identical, but it added a digital compass, a video camera and doubled its processor speed. That enabled it to run a new class of more powerful and sophisticated apps, without any radical reshaping. Once gain, that model wildly outsold its two predecessors. 

Apple's new design for iPhone 4 notoriously leaked when a prototype was discovered left behind at a bar. But despite having some real Apple hardware in their hands, bloggers at Gizmodo didn't even realize that the device would launch a new high resolution Retina Display, and they didn't know anything about its powerful new A4, the first new ARM chip Apple had developed internally with significant silicon optimizations. 

Jason Chen's prototype iPhone 4

They also didn't know — just from looking at it — that the device would launch the all new FaceTime, or that it would include the first gyroscope in a smartphone. iPhone 4 went on to become the biggest smartphone launch of its time.

The subsequent iPhone 4s built upon these enhancements with even more invisible updates, including those enabling efficient Siri voice recognition (via new mics and sophisticated voice recognition and noise canceling hardware). It also added support for the new iMessages in iOS 5, and a new leap in application processor speed with the A5 chip.

Apple's next external jump, iPhone 5, introduced a taller screen and the new Lightning connector, neither of which were widely seen as must-have features or examples of revolutionary innovation. The biggest improvement, besides its faster A6 chip and greatly enhanced camera, was support for LTE, something that many carriers at the time were just beginning to roll out beyond major cities. It went on to sell more units than ever, and lived on for another year as iPhone 5c.

iPhone 5s similarly looked little different from its predecessor apart from the metallic ring around its Home button alluding to its support for Touch ID. Its biggest leap was the surprise delivery of A7, the world's first 64-bit smartphone chip. That chip also incorporated a very sophisticated imaging engine that helped establish iPhones as excellent mobile cameras, drawing a sharp distinction with cheap Android phones that smeared memories into blurry photographs.

Apple has since launched two iPhone 6 models that actually did significantly change in their outward appearance with larger, higher resolution displays. But the A8 behind the scenes — packing a much faster GPU — did much of the work to make that larger screen possible while still retaining iPhone's lag-free user interface. 

Last year's iPhone 6s models similarly had no physically discernible features, but got a more durable frame, a faster A9 chip and packed significantly better cameras (with software support for Live Photos), along with adding sophisticated support for 3D Touch pressure sensitivity—creating distinctive shortcuts throughout the user interface, on the Home screen and within apps that added support for the new features (and tons of developers quickly scrambled to do just that). 

Despite looking little different from the original iPhone 6, iPhone 6s slightly outperformed its predecessor in its crucial launch quarter, even despite more difficult economic conditions and very unfavorable currency changes, particularly affecting China.

iPhone 6s didn't need a wildly new form factor to maintain the same unit sales surge as its blockbuster predecessor.

This indicates that while iPhone 7 might not look radically different on the outside, it won't be out of line for a new iPhone to deliver a major jump in features and capabilities due to externally invisible hardware advancements and new software that can take advantage of them and expose them to third party developers. 

New at WWDC: iOS 10

While all of the headline features of iPhone 7 aren't expected to drop until September, a new version of iOS regularly debuts at the June WWDC, often paving the way for new features on the upcoming iPhone launch. We won't know for certain everything Apple is working on related to iPhone 7 and iOS 10 for another month, but here's an outline of things the company likely — or definitely — has in its crosshairs.

A few are obvious, such as continuing work on Xcode, the company's development tool for building iOS software, and Swift, Apple's new development language that's taken off and gained enthusiastic adoption despite its fledgeling newness. 

Rumors have also already outlined potential changes to Photos, as well as Apple Music being the recipient of a targeted enhancement, specifically adding 3D Touch support for previews, enhancing content search and better exposing lyrics.