Copper vs Stormpath: What are the differences?
Copper: Password-free signups. No social network required. People sign up with their number. You get verified info. Copper is a service for developers who want a seamless, always-improving signup and signin flow in their websites and iOS apps. We remove friction so more people become and remain users, while makers ship faster and maintain less code; Stormpath: User Management and Authentication for Developers. Stormpath is an authentication and user management service that helps development teams quickly and securely build web and mobile applications and services.
Copper and Stormpath can be categorized as "User Management and Authentication" tools.