Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for automatically updating user interfaces for a mobile device. In one aspect, a first set of instructions from an automatically synchronizing data store are received. The first set of instructions are executed to provide an interface between a user and an operating system on the mobile device. The data store is automatically updated with a second set of instructions. The second set of instructions are executed to provide a modification to the interface between the user and the operating system on the mobile device.