Back in the early 2000's, in an effort to boost holiday sales for Apple products, Steve Jobs decided to hold a big fall event for select media invitees. In the years since, September has become a time to introduce new flagship products and drum up support from both consumers and investors. And for iOS developers, September unveils new opportunities to create the next killer app.

This year's event brought an impressive slate of new products and operating systems, many of which will give developers some exciting new options. Here's a breakdown of what was announced and what it means for app developers.

watchOS2 + New Watches: Apps go native

The first big product covered at September's big Apple Event, Apple Watch finds itself in an exciting position. Over the space of just a few months, it has graduated from being a product strictly for early adopters (partly due to the newness of the wearable category and to a much higher price point than similar smartwatches) to taking over a commanding majority of the smartwatch market.

As it stands, the Apple Watch provides one of the most robust experiences of any wearable on the market (even with a slate of new Android Wear devices being recently announced at IFA 2015.) Its fitness tracking is second to none among smartwatches, and it already boasts an impressive ecosystem of more than 10,000 apps. And Apple is working hard to make the Apple Watch even more of a fashion statement with several new metal finishes and over a dozen new watch bands.

Most importantly, the Apple Watch is set to receive a significant software upgrade on September 16th. This upgrade–watchOS2–opens up a whole new world of possibilities for developers. For one, apps will now have the ability to run natively on the Apple Watch, a move that should drastically increase app load time and overall performance. The updated operating system also grants developers access to the full array of onboard sensors and hardware on the Apple Watch, a list that includes the following:

Digital Crown

"Taptic" Engine

Microphone

Speaker

Heart rate sensors

Watchface complications

GPS

Accelerometer

Enterprising app developers are taking notice. "This gives us new possibilities," says Aleksander Popko of NetGuru, "but also new challenges, especially in terms of design. For example, consider how to implement an action like scrolling or changing volume. Should it be activated through gestures like sliding down or tapping? Or would using the digital crown be more intuitive?"

For developers who have been working with the Apple Watch since its release, such challenges are a welcome replacement to the limitations of the original watchOS. In addition to new hardware/sensor access, apps will now be able to use the Apple Watch to connect directly to Wi-Fi, sending and receiving information even when out of range of an accompanying iPhone.

What developers need to know about Apple Watch

Among those beginning to take significant interest in Apple Watch is Facebook Messenger, a big-time app that's hell-bent on gaining adoption in the standalone messaging space. But the watchOS ecosystem is still very new, and developers could use these powerful new hardware inclusions to build out health and fitness apps (AirStrip earned a spotlight showing during the event,) productivity planners and personal assistants, or translation tools that could quickly become Apple Watch staples. While the possibilities may not yet be endless, they're certainly growing.

iPad Pro: Size matters

One of the most interesting announcements at last week's special event was that of the new iPad Pro tablet. After months of widespread speculation, Apple has finally released a true competitor to the Surface Pro and the host of all-in-one PCs that currently cater to the on-the-go field professional. And this thing is big.

The 12.9" behemoth ships with up to 128 GB of storage and a 64-bit A9X chip that's sure to deliver blazing fast processing power. In fact, the iPad Pro's processor is almost twice as fast as the one found in the iPad Air 2 and is faster than over 80% of the portable PCs shipped in the last 12 months (according to Apple.) This tablet is ready to do some heavy lifting. It's also thin and light despite boasting four audio speakers and an ultra-sharp 264 ppi Retina display.

Apple also announced a pair of accessories to go along with the iPad Pro, the Smart Keyboard and the Apple Pencil. The latter is especially intriguing, with potential to become a staple not only for designers and artists but for heavy note-takers and chart-makers as well. Apple even brought the VP of Microsoft Office up on stage to show off just how much can be done on the iPad Pro with the Microsoft Office suite.

What developers need to know about iPad Pro

Split-screen multitasking looks to play a major role on the iPad Pro. And Apple has done developers a major favor by designing the screen on the Pro (in landscape view) to be exactly the size of two iPad Airs (in portrait view) side by side. While applications will still need to be adjusted to scale properly for the big screen, apps being used in split-screen mode will appear just as they would on an iPad Air.

It will be important to consider–and, ultimately, discover–use cases for users of the new iPad Pro. It will continue to run iOS, meaning it's unlikely to get widespread consideration as a replacement for the MacBook. But the Apple Pencil and the sheer real estate on the iPad Pro offer some intriguing possibilities for developers, especially in the realm of audio/video/photo editing and productivity.

Apple TV: Big screen dreams

Another product that has received major upgrades is Apple TV. Apple strongly believes that the future of television (and movies) lies in apps, and they're probably right. Just think of how much time you've spent in the last month on Netflix and Hulu. Apple is looking to position itself right in the middle of the family entertainment center, both literally and figuratively.

When considering the changes Apple wanted to see in its new TV experience, Apple CEO Tim Cook mentioned five factors that the company believes the modern solution needs to have. These include:

Powerful hardware

A modern OS

New user experience

Developer tools

An app store

The Apple TV looks to deliver on all these fronts, with a slick user interface and built-in search–powered by Siri through a redesigned remote control–that finds movies and TV shows across your full spectrum of connected apps. But that's not all. The Apple TV also has its own operating system, tvOS, that will allow developers to jump in and design their own apps.

Apple was quick to show off several of those apps during last week's event, including Airbnb; Zillow; a shopping app called Gilt; and a pair of new games built especially for Apple TV: Crossy Road and Beat Sports. The new remote control doubles impressively as a game controller, turning the new Apple TV into a Wii-esque gaming console. It was a pretty impressive showing and the product certainly looks primed for the big time.

What developers need to know about Apple TV

Apple TV provides a unique opportunity to create apps that a whole family can interact with simultaneously. Until now, browsing a site like Airbnb to plan a family vacation has meant huddling around a single device or passing that device back and fort within a group. Apple is looking to change that paradigm, encouraging developers to pull the whole family to the TV screen.

Since tvOS is based on iOS and features familiar tools and technologies like Xcode, Metal, Game Center, UIkit, and CloudKit, developers will have a significant head start on getting their apps ready for the big screen. Perhaps the biggest challenge will stem from redesigning TV apps to work with a remote, which offers a distinct contrast from working with touch inputs.

iPhone 6s and 6s Plus: UX teams take note

"The only thing that's changed is everything."

Apple wasn't shy in promoting its new flagship iPhones, which featured nearly identical body styles to their predecessors but some big changes under the hood. Processing power has drastically improved (as you would expect from an Apple "s" upgrade,) though battery life stayed roughly the same. But the most impressive new features came in the form of 3D Touch (Apple's new name for the "Force Touch" feature found in the Apple Watch and their new MacBook trackpads) and improvements to the camera.

Describing the science behind 3D Touch, Apple says, "When you press the display, capacitive sensors instantly measure microscopic changes in the distance between the cover glass and the backlight." In other words, the iPhone 6s and 6s Plus will sense and react to pressure put on the screen itself. And according to Jack Wu, lead iOS engineer at ModiFace, this is a pretty big deal. "Not only does it allow for more interactions within the app," he told me just after the event, "it also allows apps to show a 'shortcut menu' when force-touched on the home screen. Developers will want to adopt these features ASAP."

Along with an intriguing new touch input, the iPhone 6s and 6s Plus feature an upgraded 12 MP camera capable of recording 4K video. There's also a 5MP front-facing camera (a huge step up from the 1.2MP model found in the iPhone 6) that records video in 720p HD. This should provide a noticeable boost in quality for iOS apps that use photos and video.

What developers need to know about iPhone 6s

Both Apple and consumers seem bullish on the potential that comes with the new 3D Touch display. Pressure‑sensitive drawing, "Peek and Pop," and "Quick Actions" (the "shortcut menu" mentioned earlier) are all among the features Apple recommends developers consider including in their apps, with the latter two having the potential to radically alter user experience.

This year's slate of Apple products offers tantalizing new options for developers. How do you plan to take advantage?

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