Shame it doesn't play that way. Dead Trigger suffers the same issues any other first-person shooter has on a phone; namely, that there just isn't the input to move, aim and shoot at the same time, so you're always having to give at least one of them up.
Which is a pain in the pass.
On the plus side...it looks great. It's out now on iOS and will be out later today on Android.
Dead Trigger [$0.99, App Store]