For any status messages that do not receive focus, programmatically provide a way to alert users.
Functionality that is activated by device or user motion, for example, shaking a device or signaling to a camera, should be able to be disabled and an alternative for equivalent activation should be available.
Visual and programmatic labels should align.
Pointer input should be reversible.
Provide a single activation point alternative to complex touch activation, for example swiping, pinching, etc.