GunApp Plus is one of the best gun/weapon simulator games to be played on the iPhone. The game carries 3 fire modes like automatic, burst and single! The players are able to get tons of new weapons added and more are going to be added! The game highly features 50+ highly animated guns or weapons that start from M16's to Nuclear Weapons! The players are able to find a complete detailed description for weapons directly from Wikepedia. Also, you can find Twitter Support, which will help in twitting your friends with Gun you are shooting.
