When Apple released the iPhone 5S in September, one of its main features was the new M7 processor. Separate from the main A7 CPU, the M7 processor's function is to collect sensor data from integrated accelerometers, gyroscopes and compasses. Essentially, the M7 processor is a fitness tracker within the iPhone 5S.

Apple says it leads to "better fitness and activity apps that go well beyond what other mobile devices offer". With an API that's been available for months now, developers have begun to integrate their apps into the M7 processor. The chip even tracks your movements when a fitness app isn't open.

So which app meets your needs? We've weeded out the top five.

Nike+ Move (Free)

Nike+ Move was the inaugural app for the M7 processor, shown off when the iPhone 5S was introduced. Meant to be an introductory experience to lure you into the FuelBand gadget, the app doesn't offer too many features. It's still useful for the beginner, however, thanks to its easy to learn interface.

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Nike+ Move can measure when, where, and how you moved and uses NikeFuel to motivate you. You're encouraged to move more often and win as many hours as you can throughout the day. The app shows how you moved with a breakdown of running, walking, and other movement. It gets social too, letting you compare your activity with that of friends and other Nike+ Move users.

Pedometer++ (Free)

The Pedometer++ is basic, but it offers pedometer functionality in a clear, free way.

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It lets you keep track of your daily and weekly step counts. You can set the app to dynamically show your current step count as an applications badge on the iPhone's homescreen. You can set goals and Pedometer++ will let you know when they have been reached. Additionally, steps are translated into distances.

RunKeeper (Free)

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The RunKeeper app will track walks longer than 15 minutes throughout the day and records them in a daily log. Runs are also tracked, and steps per minute included in the data of each running activity. You can then compare your workouts, seeing elevation, stride length, and more.

Moves ($2.99)

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Moves sets out to be more than just a step tracker, showing your movements throughout the day. It tracks walking, cycling, and running, and it puts everything in a timeline so you can look back and see where you've been and how long it took you to get there. You can plot routes on a map, see calories burned for each activity, and set step goals throughout the day.

Fitbit (Free)

The M7 processor functionality within the Fitbit app is like Nike+ Move. It's meant to get you to buy Fitbit hardware, which costs roughly $100/£79.

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The Fitbit app lets you track your steps in a day, miles, and calories burned through the M7 processor. Within the app there's also the ability to track food eaten and calories consumed.