A method includes, in a user device (24) that is configured to communicate over a network (32), preloading an application (26) in a background mode in which content presented by the application is hidden from a user of tire user device. At least part of the content presented by the application is pre -rendered in an off-line pre-render mode in which fetching of content over the network to the user device is not permitted. In response to an action by the user that requests to access the application, a switch is made to presenting at least the pre -rendered content to the user in a foreground mode.