Apple's latest flagship phone, the iPhone 5S, is going on sale this week.

The iPhone 5S is packed with a fingerprint sensor, better camera, and faster processor.

But for the those who follow the quantified self movement, where people track their health with things like wearable activity trackers and smart scales, the more interesting new elements are the M7 motion coprocessor and the Core Motion API. 

The M7 is a new chip in the iPhone 5S that continuously measures gyroscope, accelerometer, and the compass in the device. So that means apps will always be able to know if you're stationary, walking, running, or driving. 

Apple will allow developers to tap into the chip through the Core Motion API. The idea is to fuel a new generation of activity tracking apps. 

That raises the question of whether we really need another device to track our activities. 

Already, there's a great app called Moves that runs in the background to track a variety of activities like walking, running, cycling, and driving. Back in June, Moves tracked over 2 billion steps per day. Jawbone Up, a wearable fitness tracker, only tracked more than 1 billion steps per day at that point. 

"It's great to see that Apple supports this use case better!" Moves CEO and Designer Sampo Karjalainen tells Business Insider via email. "They are doing the right thing by optimizing the hardware for this use case. We're really excited to get to use the new APIs. This validates that smartphones are a great platform for mainstream activity tracking."

But wearable tech expert and Synapse VP of Technology Skooks Pong doesn't think that Apple's M7 chip will this will totally replace the need for additional devices. 

Synapse is the engineering firm behind the Nike FuelBand fitness tracker. About a decade ago, Pong worked on early prototypes of Microsoft's SPOT smartwatches. Those watches failed to gain traction and Microsoft stopped supporting them.

"There will always be a need or market for some specific devices to track or monitor our activity or health," Pong says. "Could be athletes who can't or don't want to carry a phone or more specialized health monitoring devices that leverage the connectivity of the smartphone." 

Given that Apple seems likely to release a smart watch next year, we bet Apple will integrate this tech into the iWatch. 

See Also:

Check Out The Awesome New Slow-Motion Feature On The iPhone 5S Apple Is Advertising Its New Plastic iPhone 5C Instead Of The Sleek iPhone 5SEverything Apple's New iPhones Can Do

SEE ALSO: Apple And Samsung Are Best Poised For A Smartwatch, Says Wearable Tech Veteran