When the iPhone 5s launched with the M7 motion coprocessor on September 20, Azumio’s ARGUS fitness app was updated that same day with M7 compatibility. I’ve been an ARGUS user for quite awhile, as it syncs with my LifeTrak and can also independently track steps in the background throughout the day even without a wristband.

The app is now the #1 free Health & Fitness app in the App Store and has been featured as one of the top “Designed for iOS 7” apps.

Seeing that the app gained M7 compatibility so quickly – it was the first one that I noticed and I haven’t been able to find one that added it before them – I was curious about how ARGUS was able to take advantage of the M7 so quickly. I had the opportunity to speak with Peter Kuhar, product manager for ARGUS at Azumio. He was able to break down some of the intricate information surrounding the M7.

Battery life

For pre-iPhone 5s devices, ARGUS usually drains about 20-30% of battery life per day while running in the background. The app continually checks for motion and calculates the distance and number of steps using the accelerometer and GPS. With the M7, however, the app does not need to be running in order to keep track of the number of steps – all of that data is tracked by the M7. As such, ARGUS no longer takes up any battery power while running in the background and the stated battery life from Apple – 10 hours 3G talk time, 250 hours of standby – will stay exactly the same.

Data storage

The M7 stores up to seven days worth of step information. When you first download ARGUS, the app polls the M7 data and can retrieve all of the historical information – so you start out with a good base of data.

The M7 APIs allow developers to query information about the user’s current transportation status (whether they’re in a car, walking, not moving, etc.). From Apple’s developer site: “The framework can also distinguish different types of motions reflective of travel by walking, running, or automobile. Health and fitness apps can take advantage of that data to give users performance and workout results, and navigation apps can use it to change the type of directions they provide.”

The future of Apple’s Maps application will see the M7 more deeply integrated.

Android adoption

Azumio has been hoping for a motion coprocessor for quite some time. Rather than having the battery-hog CPU running all the time, placing in a motion coprocessor allows the phone to store all of the information while the CPU can sleep or focus on other tasks. The company told me they were in talks with Android manufacturers about placing motion coprocessors in their phones, and now that Apple has been boasting about this new piece of hardware, there’s a good chance other manufacturers will follow suit. The Moto X has its own version of motion tracking and 4.3 includes support for activity detection, but nothing matches the low-power capabilities of the M7.


The M7 is one of the most exciting features of the iPhone 5s, especially for fitness-loving users. Nike’s app, which was demonstrated on stage during the iPhone media event, will be receiving M7 compatibility in the near future. A few other apps, like Strava Run, have also added compatibility in the past week.

ARGUS is available for free in the App Store.

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