The Monocle from Studio KMD consists of two parts. It's a holder that slips onto your belt and an app that triggers a bright red flashing light. Hang it down over your rear and bike away with your iPhone flashing behind you.
The Monocle takes advantage of the iPhone's built-in flash, but adds a red filter. The big question surrounds battery life. The app automatically adjusts the number of flashes per second depending on the length of the ride.
The Monocle creators say their experiments have shown that a 15-minute ride with the light flashing three times per second uses about 7 percent of the battery life. The app also gives off warnings when the battery is running low.
If you hurry over to Kickstarter, you can get in on the Monocle action at the early-bird $12 pledge level. The regular pledge price is $15.