BulletDrop
Gushroom
Bulletstop - fps logic puzzles
Hot dogs
Hornady
Chairgun Elite Ballistic Tool
JetLab, LLC
Lapua Ballistics
RightSpot Ltd
GeoBallistics
Sheltered Wings, Inc.
Arken Ballistics
Pango Optics
Hornady Reloading Guide
Applied Ballistics
Range Buddy
Atriarch Targets