To effectively manage users across multiple apps, you can consider using a centralized user management system or an identity and access management (IAM) platform. These platforms allow you to easily manage user access, permissions, and credentials across different applications.

Popular options for user include:

1. Okta
2. Azure Active Directory
3. OneLogin
4. JumpCloud
5. Auth0

These platforms offer features such as single sign-on (SSO), multi-factor authentication (MFA), user provisioning/deprovisioning, and centralized user directories. Additionally, they often provide API integrations with various applications, making it easy to manage user access and permissions across different systems.

Before selecting a platform, consider your specific needs, such as the number of applications you need to manage, the type of authentication mechanisms required, and the level of automation and scalability you need.

By implementing a user management platform, you can streamline the user management process across multiple apps, saving you time and ensuring consistent access control across your systems.