The problem is timing. A flash that is 10 milliseconds too late is useless. Real cameras have a dedicate hardware output that will send a precise digital signal at the right instant to trigger an external flash. Our note (and every cell phone I am aware of) lacks this hardware output (sometimes called a "hotshoe" on cameras). Without this output, your only choice is a flash unit that detects your flash and fires instantly or a really bright, constant light. To be honest, your best bet is a good flashlight of some kind.