In unveiling the iPhone 5s this week, Apple executives proudly pointed to several hardware firsts. Among the most obvious are the new Touch ID fingerprint sensor in the home button and the move to the 64-bit Apple-designed A7 processor. (Samsung was quick to announce that it's developing devices with 64-bit chips, too.) Along with those under-the-hood advances comes the most intriguing change: the new M7 "motion coprocessor."

Apple's iPhone 5s.

Apple hasn't publicly detailed just how the the M7 works, though it has added a new set of APIs, dubbed CoreMotion, that developers can access when writing iOS 7 apps. Nike, in fact, has already announced the first M7-enabled app.

Apple did at least offer a broad overview of its intentions for the coprocessor: "Every iPhone 5s includes the new M7 motion coprocessor that gathers data from the accelerometer, gyroscope and compass to offload work from the A7 for improved power efficiency." That's from Apple's press release announcing the 5s, and it mirrors what Phil Schiller, Apple's senior vice president of worldwide marketing, said on stage during the iPhone announcement Tuesday.

This defines a huge function of the M7 -- to process the increasingly large amounts of data people can generate while carrying a sensor-laden device. Triangulating this data takes processing power, but not a huge amount of it. (Remember, earlier iOS devices, including those that used less powerful non-Apple processors, were able to work with this kind of data.) Essentially, the A7 would be overkill for the more basic tasks of aggregating and processing motion data.

Offloading that low-level data capture and processing to a low-power processor delivers two big advantages: It increases battery life (always an important goal for any mobile device), and it reduces the heat generated by the main processor. That should increase the life expectancy of a device and keep it from getting hot. As processors grow in capacity and performance, they typically need more power to function (and therefore, typically, produce more heat). One explanation for the M7 is simply that Apple needed to offset some of the increases in power demand and heat production that are a consequence of the A7 chip's improved performance.

The second big advantage of the M7 is that it effectively boosts the performance of the main A7 processor. With less work to handle during iPhone use, the A7 has more processing cycles available for other needs like launching and running apps. With iOS 7 being better at multitasking, this gives the iPhone 5s additional performance dividends.

Apple is also touting the M7 for tasks that take place when you're not actually using your iPhone. Since it uses less power than the A7 processor (and potentially less power than earlier A-series processors), iOS 7 and apps coded to take advantage of it can perform continuous monitoring in a way that might otherwise be impossible or unwieldy because of power constraints.

Apple is specifically pitching this as an advantage for fitness and activity-tracking apps, saying that, thanks to the M7, the iPhone 5s "continuously measures your motion data, even when the device is asleep, and saves battery life for pedometer or other fitness apps that use the accelerometer all day."

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Fitness and activity apps are excellent uses for the M7, and the continuous monitoring Apple describes could soon make some activity tracking devices unnecessary. If the iPhone 5s can replace those devices, it could become a development platform for a variety of proactive health and fitness tools. Your iPhone could soon be encouraging you to get in better shape by suggesting that you go for a walk or a run at lunchtime, or by finding longer or more challenging routes for you to follow if you already walk or run regularly. Or it might remind you to park at the back of the office parking lot to increase your walking time, or suggest you walk to a nearby coffee shop rather than drive.

Beyond traditional fitness activities, the M7 could turn an iPhone 5s into your personal ergonomics coach, suggesting that you get up and stretch during the workday and offering reminders about good posture if the phone detects you slouching.

In short, the M7 could allow the iPhone to become a digital fitness coach that encourages you to make small changes to your routine that add up over time.

The chip could also offer new levels of integration between iOS hardware and connected mobile health devices. A user's activity level could be correlated with data from devices that measure blood pressure, heart rate or blood oxygen levels. That level of data could vastly improve treatment and activity planning for people with cardiovascular disease and could even provide important information in an emergency room setting -- particularly since the data would be available on the phone even if the person wasn't conscious.

This could even be an early indication of upcoming iOS integration with the expected iWatch, especially since some reports have indicated Apple might include health monitoring sensors in that device. It's notable that Apple has been on something of a hiring spree for health and fitness engineers of late.

Continuous monitoring could also open the door to new accident awareness solutions, too. Instead of an elderly person needing to use a device like Life Alert to call for help, an iPhone could detect a fall and ask if the person needs aid (reversing the old "I've fallen and I can't get up" scenario). In a car, it could replace the sensors that services like OnStar use to detect a crash (and thanks to location services, the iPhone could provide all manner of useful data to emergency responders).

Another M7 advantage could be to automate other actions related to travel or navigation. When an iPhone detects you're driving, it could offer up real-time traffic information -- even if you haven't asked for directions because the device will have learned your typical commute. It could also allow for a seamless transition between driving and walking directions, simply because the Maps app would know you've stopped driving and gotten out of the car.

Apple or third-party developers could even take a cue from Google/Motorola's MotoX, which can launch a camera app when the phone is lifted in a way that indicates the user is positioning to take a photo. Motion detection like this could be built into a range of apps.

That level of automation at the device level is pretty incredible, but if you combine it with home automation technology, it becomes even more powerful. Simply by having your phone in your pocket, your front door could unlock automatically. When you get up from the couch and head to bed, the iPhone could signal a system to turn off all the lights throughout the house and adjust your thermostat settings. Combined with an Apple TV, a movie or TV show you're watching (from iTunes, Netflix, or other supported services) could be paused automatically if you get up to make a snack or use the bathroom.

Although it may seem like something small that just improves battery life, I suspect that the M7 will become a very important feature in iOS devices over the next few months or years. With the potential it offers to developers, it will probably become a standard feature on other iOS devices down the road. At the same time, given the recent debate about privacy in the wake of the NSA scandal, Apple will need to demonstrate to customers -- particularly its business customers -- that all this personal data is stored securely, deleted at some point when it's no longer relevant, and ideally -- like the information gathered from the Touch ID sensor in the iPhone 5s -- is never transmitted to Apple in the first place.

Ryan Faas is a freelance writer and technology consultant specializing in Mac and multiplatform network issues. He has been a Computerworld columnist since 2003 and is a frequent contributor to CITEworld.com. Faas is also the author of iPhone for Work (Apress, 2009). You can find out more about him at RyanFaas.com and follow him on Twitter ( @ryanfaas).

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