Magpeye is a tool for replaying and deciding close line calls in Badminton.
Just put you smartphone on a tripod and focus it on one line of a Badminton court and Magpeye automatically detects collisions of the shuttlecock with the Badminton court.
You can replay detected collisions to decide close line calls.
Magpeye also gives its own evaluation of each collision, telling you how certain it is the that the shuttlecock touched the line or hit the court right or left of it.