This app allows the user to use their phone as a launching device for simulated siege weaponry. The calculated points of landing are drawn on a map.

The user can select between a trebuchet (catapult), an English longbow, or a modern mortar.

All the trajectories are calculated based on the exact angle and direction the phone is pointing when the launch button is tapped.

Hitting a target takes some practice.

A target can be marked as a bulls-eye. The relative elevations of source and target can be considered.

There is a visual reference section describing the three weapons.