The "Firebuddy"
A "fire buddy" is a small drone like robot in Metal Arms: Glitch in the System that you can get on certain levels. The firebuddy is a small self-propelled device that will double the player's weapons-fire output, as it mimics the weapon the player is currently holding (with the exclusion of secondary items & weapons), and fires in synchronous with the player.
Other
It should be noted that on difficulties higher than "Medium", (E.g., "Hard" and "Nuts of Steel") many of the crates containing firebuddies will become closed, and inaccessible to the player, and even on medium difficulty the firebuddy does not spawn on some levels. This plus the name means it can be inferred the firebuddy is a gameplay balancer for players struggling with Metal Arms' rather rapid difficulty curve, as Firebuddies only appear at points in the game where the difficulty bar is suddenly raised.