Big problems with this. Firstly, it's not safe to take your hands off the handlebars to give signals, surely a switch on the bars to be able to flick with your thumb to show a left or right indicator would be better?
Secondly, the front page of their Kickstarter campaign shows a cyclist holding up his left hand, but the arrow indicating a right turn?
Confusing and not practical. Sorry. Another gimmicky product.