An app marketplace is a platform where users discover, buy, download, and install mobile applications. In practice, it is more than a catalog: it also enforces publisher identity, app review rules, signing checks, payment handling, and update delivery. Because it sits between developers and users, it is a major trust boundary in mobile security.
App marketplaces matter to cyber security because attackers often try to abuse the same workflows users trust. Common threats include fake stores, cloned listings, malicious lookalike apps, and phishing pages that imitate legitimate install or payment prompts. Defenders reduce risk by verifying package signatures, checking developer identities, monitoring for brand impersonation, and warning users when they leave the official marketplace. When app distribution expands to alternative marketplaces or web installs, security teams should review the new path carefully, since every added channel can create more opportunities for fraud, confusion, and unsafe software delivery.