A service provider system may include an application fulfillment platform that delivers desktop applications to end users (e.g., to physical computing devices or virtual desktop instances). An application delivery agent installed on an end user's device may send requests to access platform control plane services on behalf of the agent or the end user (along with security credentials) and may retrieve messages directed to the device from a queue on the platform. Messages may be placed in the queue by control plane services in response to agent requests. Messages may include instructions for the agent to perform installing, uninstalling, updating, or reinstalling a virtualized desktop application package on the device. The agent may request and retrieve (from the queue) information about the intended (or assumed) installation state of applications on the device, compare it to locally stored information about the actual state, and initiate corrective action, if needed.