Metronome with midi in and bright light?
 

I'm thinking about a midi setup with a band where the drummer doesn't need a headphone setup. What's your cheapest recommendation? I've heard about some of the high end options like the Laser and the Q-strobe metronomes, but I couldn't even figure out how much they cost.

Some DAWS let you put the Metronome in a window and make it big.
Have the drummer use a pad and drum trigger brain so he can tap the tempo to start things off the DAW. And he can watch the on-screen metronome.
IEM is still the best.

What about iPhone/iPad apps?

I`ve never heard of anything like this but it sounds like a great idea!