More than 1,500 developers in the UK have banded together to sue Apple, alleging that the tech giant's App Store fees are "excessive" and harmful to both developers and consumers. 

The class-action lawsuit, led by Sean Ennis, a professor at the University of East Anglia Centre for Competition Policy and a former OECD economist, is seeking £785 million (€912 million) in compensation for the affected app creators.

At the core of the legal challenge is Apple's policy of...