A synchronization system is provided that distributes synchronization system-based applications and synchronization system-based application extensions and their associated resources and components (hereinafter "plug-in applications" or "plug-ins"). Components are maintained such that any synchronization system-based application instantiation may be changed or updated by the synchronization system. In one specific example using the synchronization system, each synchronization system-based application or plug-in is self-contained and self-updateable through a synchronization system synchronization process. A further benefit is that the synchronization system and synchronization system-based applications may be extended independent of device type or operating system. Thus, a system is provided for synchronizing one or more plug-in applications. In one example, the system for synchronizing plug-in applications inclides a synchronization system having at least one distributed database that is configured to store a plug-in application, and a schema for the database. Optionally, the distributed database may be configured to store plug-in application instantiation information, synchronization system-based application association information, role, permissions, access control rights, and data associated with the plug-in application. In one example, each distributed database has at least two instances, and the plug-in application (and optional resources and components) is stored in at least one instance of the distributed database. As described herein, the synchronization system is configured to synchronize the plug-in application (and optional resources and components) between the instances of said distributed database.