Blinkie lights are key to safety when riding at night, but leaving home before dark without one is pretty easy to do. Few leave home without their phone, and Philadelphia based Studio KMD figured it would combine a custom holster and iPhone app to turn your phone into a rear blinkie light. It’s never going to be on par with the latest 1 and 2 W rear safety lights out there that can be seen for miles, but it’s far better than nothing. Though I can’t see myself using my phone (and its limited battery) as the most expensive rear blinkie ever, I can see the appeal from minimalist, fashion oriented types. See their Kickstarter page for more info and to pre-order your own case for $15.