Apple has warned App Store developers that apps and games that haven't received an update in a "significant amount of time" could be pulled from the platform.

A number of developers shared the "App Store Improvement Notice" they received on Twitter, with one describing the move as an "unfair barrier to indie developers."

"This app has not been updated in a significant amount of time and is scheduled to be removed from sale in 30 days. No action is required for the app to remain available to users who have already downloaded the app," reads the notice, shared by mobile developer Protopop Games.

"You can keep this app available for new users to discover from the App Store by submitting an update for review within 30 days. If no update is submitted within 30 days, the app will be removed from sale."

In a FAQ on the Apple website (spotted by  Eurogamer), the company confirmed it is implementing an "ongoing process of evaluating apps, removing apps that no longer function as intended, don't follow current review guidelines, or are outdated."

Apple explained that applications in all categories of the App Store are being evaluated as part of the process -- so the cleanup isn't limited to games -- and confirmed that developers will be asked to submit an update within 30 days.

"If you are unable to make the changes within this time frame, your app will be removed from the App Store until you submit an update and it is approved. Please note that apps that crash on launch will be removed immediately," continued the company.

The iPhone maker told developers to read the latest App Store Review Guidelines to ensure their software is ready for future changes.