My favorite gun app is, without a doubt, Gun Disassembly 2 (read my full review here). For those of you who have not heard of it before, the app lets you explore and disassemble/reassemble a wide range of firearms. It has everything from the Ruger LCR to the M134D ‘Minigun’ and even a few WWII field artillery guns. The models are accurate and the gun can be fired to see how all the moving parts work. X-Ray/Cutaway modes allow you to see how the gas systems and trigger mechanisms function. It is the only app I use on all mobile devices: my Macbook Air, Android phone and my iPad. Each time I play it I learn a lot. I have even used it to figure out how to fit some old mil-surplus guns I own.
The company that makes it, Noble Empire, has just released a new version called World of Guns: Gun Disassembly. World of Guns has all the features of the old version but adds a number of mini-games which test your understanding of guns, as well as adding a range mode which lets you shoot the gun models First Person Shooter style.
World of Guns (and Gun Disassembly 2) get a new gun model added about once every month. The game is free and comes with just a couple of gun models and you must purchase additional models. I recommend buying the “Lifetime Access” pack, which costs $49.99, rather than the smaller gun packs.