For example, using your iPhone, Mac and TV at the same time.
A more extreme example: using your iPhone to Facebook while you look up a store on the IPad and your partner shows you a pic on his android of your favorite star in a compromising position.
A fun example: three friends sharing their tech devices to coordinate an event. This would also be called a triple banana split.
In relation to douple-scoop: when a person or persons uses two electronic devices at the same time.