A free app for Android, by FRVR.
Krunker FRVR is a fast-paced first person shooter with a lot of content. You can choose from a wide variety of weapons, from assault rifles, machine guns, rocket launchers, grenades, and even a ton of cosmetic items.
There are over 40 unique weapons to choose from. You can customize your character with all kinds of items, from hats, glasses, hairstyles, and even body armor. The armor and weapons are cross-platform, so you can use them on any device.
There are a lot of different maps to play on. You can play in the open world, or the world of the game.