Apple App Store, Google Play store duopoly questioned again as US justice department circles

The start of broad government antitrust investigations into the U.S. technology industry has revived questions about Apple Inc. and Google’s dominance of app stores and the fees they charge to developers.

U.S. enforcement agencies recently split oversight of the largest U.S. tech companies, with the Justice Department focusing on Apple and Alphabet Inc.’s Google, according to people familiar with the matter.

The government hasn’t said why it’s grouping Apple and Google under Justice, or how it might apply antitrust law to their businesses. But a lawsuit filed Tuesday underscored growing developer ire over app stores, the vast digital bazaars showcasing millions of games, productivity tools and other software available for download onto handheld devices.