Makers of apps purged by Apple say it holds the key they need to get back in

Last year, Apple announced that it had created tools to help people limit the time they and their children spent on their iPhones. Around the same time, Apple began purging from its App Store several apps that offered similar services.

Now 17 companies affected by that purge say they have a technical answer to the privacy concerns that Apple cited for dropping them.

The companies have proposed the creation of an application programming interface, a common bit of software that enables computer programs or apps to work with one another. The companies said the API could tap Apple technology that would allow them to track screen time without invading privacy.

“Right now, technologically, only Apple has the right to do it on their devices, and we believe Apple should let everybody get a go,” said Viktor Yevpak, head of Kidslox, a parental-control app that has been singled out by Apple.

The companies’ move puts added pressure on Apple before its annual developers conference this week, when the iPhone maker interacts with thousands of app makers and lays out its vision for the year.

Apple is increasingly on the defensive over its tight control of the App Store. The high fees for access to the App Store and competition from Apple’s own apps are drawing accusations that the Cupertino company is abusing its power.

Spotify recently complained to European regulators that Apple used the App Store to give its Apple Music service an unfair advantage. Dutch regulators are investigating whether Apple abused its control of the App Store. Last month, the Supreme Court allowed an antitrust class action to move forward, saying consumers have the right to try to prove that Apple used the App Store to raise apps’ prices.

And Kidslox and another parental-control app, Qustodio,...