1. A method of synchronizing application installations between devices, the method comprising: linking, at a network service, user devices associated with a user; in accordance with the linking, synchronizing application installations and uninstallations through the network service between the user devices, wherein by default when an application is installed or uninstalled from one user device, the synchronizing causes the application to be installed or uninstalled at another user device; maintaining global installation information and local installation information, the global installation information indicating which applications have global install status and indicating which applications have global do-not-install status, the local installation information indicating which applications have local-only install status on which of the devices and indicating which applications have local-only do-not-install status on which of the devices; and wherein the synchronizing is performed according to the global installation information and according to the local installation information, and wherein to determine which applications will be installed and uninstalled on which of the devices, the local installation information is given priority over the global installation information when determining which applications to install and uninstall on any of the devices.