Community member Sagatron pointed me towards the iPhone version of Robokill, which is free today. It’s a mobile port of the Flash shooter, which you can play here. I found the controls to take some getting used to, as the dual virtual analog sticks and variable movement speed can make it a bit of a pain to navigate. When you add ledges that lead to instant death if you fall to your doom, that’s not exactly helpful either.
Still, it’s a decent enough twin-stick shooter with some leveling up and an inventory for applying a ton of weapons to your robot. Since it’s free, it’s worth a shot if you have more than a passing interest in this type of game on your iPhone. You’re probably better off playing it on the PC if you ask me though.
[Found a free App? Think it’s good? Hit up Jim Sterling (iOS & Android) or Maurice Tan (iOS) and let ’em know. Please do so — finding good free games is hard!]