NEW YORK (AP) ― A bug in Apple’s new iOS 8 software for mobile devices is prompting the company to withhold apps that use a highly touted feature for keeping track of fitness and health data.

Apple says it hopes to have HealthKit apps restored to its app store by the end of the month. Affected apps include Carrot Fit, WebMD and AskMD. Apple didn’t provide details on what went wrong.

The iOS 8 software became available Wednesday. HealthKit is supposed to create a central repository for health and fitness data, so that apps have a better picture of your overall wellness and can even recommend trips to the doctor.

Apple’s new iPhones have sensors to monitor fitness activities, and its upcoming Apple Watch will have a heart-rate monitor.