Abstract: In general, the subject matter described in this specification can be embodied in methods, systems, and program products for identifying proximity of a mobile computing device to another mobile computing device. A computing system determines that a set of mobile computing devices are geographically proximate to a first mobile computing device based on identifying that each of the mobile computing devices received a first type of signal from an emitting device for which the first mobile computing device also received the first type of signal. The computing system determines a subset of the mobile computing devices that share a physical space with the first mobile computing device based on identifying that each of the mobile computing devices emitted a second type of signal that was detected by the first mobile computing device, or detected the second type of signal that was emitted by the first mobile computing device.

Abstract: A computer system displays: a view window including an initial portion of a document, a scroll icon at an initial scroll icon location on the display, and a marker icon that is distinct from the scroll icon. The computer system detects a scrolling input and in response moves the scroll icon to a target scroll icon location on the display wherein the target scroll icon location corresponds to a target portion of the document. In some embodiments, the computer system scrolls the document towards the target portion of the document and concurrently moves the marker icon towards a target marker icon location on the display that is proximate to the target scroll icon location, where the scrolling speed of the document is determined based on the distance between the marker icon and the scroll icon.

Abstract: In general, the subject matter described in this specification can be embodied in methods, systems, and program products for identifying proximity of a mobile computing device to another mobile computing device. A computing system determines that a set of mobile computing devices are geographically proximate to a first mobile computing device based on identifying that each of the mobile computing devices received a first type of signal from an emitting device for which the first mobile computing device also received the first type of signal. The computing system determines a subset of the mobile computing devices that share a physical space with the first mobile computing device based on identifying that each of the mobile computing devices emitted a second type of signal that was detected by the first mobile computing device, or detected the second type of signal that was emitted by the first mobile computing device.