The iPhone 5s and its M7 motion coprocessor are opening the doors to a new wave of fitness apps that take advantage of the low-power motion processing available with the motion chip. One of the first apps to use the data from the M7 is the Argus - Motion and Fitness Tracker from Azumio.
The big draw of Argus for many people will be the step tracking, which is pulled from the M7 on the iPhone 5s and from GPS with older devices. I've tested the Argus step data on the iPhone 5s, and it compares favorably with the data from the Fitbit Flex -- with one caveat. For the step tracking on the iPhone to be accurate, you have to always have your phone on your person, which can be a big problem for some folks.
Besides steps, Argus also tracks your weight, workouts, water consumption, coffee consumption, sleep and more. If there is a parameter that is now shown, you can search for it and add it to your profile. I do a lot of kayaking, so it was very convenient to find that rowing was included in the database, even if it wasn't on the main screen. The app is designed to automate your data collection by tying into your Withings scale and other apps that monitor your sleep, heart rate and so on. You can also enter in your data manually,
As you enter data, you can view all your stats at once in a timeline view that has a honeycomb layout. There is also a "Trends" option in the settings that allow you to view any two items that you track. You can compare your steps with your weight or your cups of coffee with your sleep duration, for example. You can also view the history of an individual item by tapping on it in the Timeline view.
Argus manages to pack a lot of information into the app, but you have to get accustomed to the UI before you can take advantage of the data that is being stored. I am used to the Jawbone Up and the Fitbit Flex and prefer those apps to Argus. If you've never used a fitness tracker, though, you may be able to jump right into Argus without a second thought. Regardless, it's worth a look for iPhone 5s owners who want to use the M7 to track their steps and overall fitness.
Argus is available from the iOS App store for free.