Algodoo

New display layout and a new display value: the speed of the bolt(projectile)
and rounded numbers no 1.2325346346342...(would be 1)

4 displays:
left for cached nails
top right for the amount of nail you shot
(middle) right for shootdistance
bottom right for the bolts speed (m/s)

green light is on when you can shot else the red

used the code from kilinichs hingemousecursor(forgot the name) to make a point at the target its red when you can shoot and more transparent if not

and there are some eyecandy
the main idea for the shape was the medics gun from tf2

have fun