Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for annotating search results. In one aspect, a method includes receiving a notification request, the notification request for identifying when to send a notification from the server system to a device, the notification request includes a device identifier, message text, and a location identifier. The method also includes receiving information corresponding to a current location of the device and information corresponding to an identity of the device. The method also includes determining that the information corresponding to the current location corresponds to the location identifier of the device from the notification request and that the information corresponding to the identity of the device corresponds to the device identifier from the notification request. The method also includes sending the notification, including the message text, to the device.