Apple has recently released watchOS 2, which promises to have apps running natively. Taking advantage of this feature, Runkeeper, a multiplatform fitness tracking app, was rebuilt around the new OS and was launched to run on the smartwatch without being tethered to an iPhone.

Runkeeper has been on the Apple app store since 2008. Its 40 million users use it for tracking statistics for fitness activities, such as running, cycling and walking. Moreover, the app tracks progress and coaches the user on how their current performance compares to previous ones.

The app also monitors heart rate and weight and facilitates audio tracks to make the activity more enjoyable. The only problem was that it needed to be tethered to a handset, which means running with a phone — not entirely an ideal scenario. Now Runkeeper tells users to bid goodbye to this hindrance.

"With the completely rebuilt Runkeeper app for Apple Watch, you can actually leave your phone at home on your run and still get all the tracking goodness you love," writes Runkeeper. "This is for all of you who have been saying since 2008 (Runkeeper's birth year) that you'd love to track your runs but can't imagine running with a phone."

It is quite intriguing how the rebuilt app functions when its previous version required GPS, a feature not present in the Apple Watch, thus requiring the user to be tethered to a phone. Some suspect that it is done through Wi-Fi data.

With an untethered and independent Apple Watch, Runkeeper users will be provided with a heart rate monitor and the ability to change the activity type from the wearable itself. A recap of stats after the activity, which includes distance, average speed, average heart rate and duration, will also be displayed on the smartwatch.

However, the app developer notes that for the watch to be calibrated, users must bring their iPhones on their workout several times. Moreover, without the GPS on the phone, the map will not be displayed on the Apple watch. The summary will also be limited and will not populate the pace charts and split times.