Lawyers for Alphabet's Google and "Fortnite" maker Epic Games squared off before a U.S. appeals court in California on Monday, as Google tries to undo a jury verdict and a judge's order forcing it to revamp its app store.

Epic accused Google in a 2020 lawsuit of monopolizing how consumers access apps on Android devices and how they pay for transactions within apps.

Ellsworth told the appeals court that U.S. District Judge James Donato improperly allowed Epic to turn the Google trial into a “do-over” that excluded the Apple app store as a rival in the market definition that led to the jury’s verdict in its case.

Before we explore what the Play Store needs to copy from the App Store, let's discuss what it shouldn't. If there's one major way Google can differentiate its app store from Apple's, it's how you discover new apps and games. Right now, the Play Store is so difficult to use that it's easy to completely miss exciting new apps and games.

Google is preparing to head back to court on Monday to appeal a ruling that found its app store was a monopoly — one of three major antitrust suits against the tech firm.

A federal appeals court panel in San Francisco appeared skeptical of Alphabet Inc.’s argument that its competition with Apple Inc. in smartphones is sufficient to justify overturning a jury verdict that declared an illegal monopoly for Android apps.