mouse4all is an accessibility solution that allows the use of Android tablets and smartphones without touching the screen. It enhances the autonomy of its users enabling the access to Internet, social networks and all types of applications. mouse4all allows the connection of switches, mice, trackballs and joysticks to any Android device.
A switch mouse is a device which emulates a conventional mouse with one ore two switches that move the mouse pointer horizontally, vertically, and in some models, diagonally. It also emulates the functions of the conventional mouse buttons (depending on the model: dragging the mouse; left, middle, right and double click). In case of only having one button, the device should have a scanning system to choose the action that the mouse should do.
Source: AT Observatory