Updated Software using the super-hyped HealthKit API in iOS 8.0 has been pulled by Apple from the App Store due to a bug in the technology.

Healthkit, new in iOS 8.0, is designed to allow applications to share and analyze information about a user's exercise routine, heart rate, weight, and so on, now that gadgets nagging about fitness are all the rage. The software interface is crucial for Apple as it ties in with the upcoming Apple Watch that has sensors for measuring one's wellness so one can boast about it on Twitter.

App developers were invited to build and release software to take advantage of the new API in time for the iOS 8.0 launch – indeed, Apple pushed its latest mobile operating system to compatible iPhones, iPods and iPads today.

However, obtaining apps that rely on the new mega-touted HealthKit API is proving to be another story: Apple has confirmed it has, in a face-saving move, pulled Healthkit apps from its store as the API is not ready for primetime.

Brian Mueller, who develops the Carrot fitness app, complained earlier today that the Cupertino giant is holding back HealthKit apps due to unfixed glitches. And Apple's bug may not be fixed when the company puts its new iOS 8-powered iPhone 6 and iPhone 6 Plus handsets on the shelves on September 19.

Mueller's Healthkit-supporting version of Carrot, due to go live today, is absent from the App Store.

Mueller's since deleted tweet, which read: Sounds like HealthKit won’t be working at all this week. And there’s no ETA for when a bug fix will go live. (Screenshot by 9to5Mac)

His complaint was backed by a blog post on 9to5Mac citing developers also upset about disappearing Healthkit software, and a tweet from Mac blogger Federico Viticci – who says he was tipped off by anonymous app programmers:

Apparently Apple found a HealthKit issue on their end and have temporarily removed all HealthKit compatible apps. No ETA on fixes. — Federico Viticci (@viticci) September 17, 2014

A health-monitoring application from WebMD that uses Healthkit was officially released on Wednesday, but is now unavailable from the App Store. Older versions of pulled programs, which do not rely on HealthKit, are due to be restored to the online shop while the bugs are ironed out.

"Our new app had been available for download in the app store until 1030 [PDT] this morning, at which point it became unavailable," a WebMD spokesperson told The Reg within the past hour.

"We have been in contact with Apple about this issue, and expect to see the previous version of our app (v5.2) back in the store on a temporary basis."

The iThing designer did not respond to our request for an explanation. ®

Updated to add

Apple has told reporters in the past few minutes that there is a bug, and it'll be fixed by the end of the month.

Apple's full statement on today's iOS 8 Healthkit issue, via email: pic.twitter.com/xDhuKrLZQe — Tim Bradshaw (@tim) September 17, 2014