There are plenty of cycling apps for mobile devices, and even some accessories that allow them to be used as bicycle computers. It isn’t the biggest accessory segment out there though, so anything new is always welcome. The VeloComputer is a Bluetooth 4 bicycle sensor that attaches to your bicycle and sends data to a connected iPhone 4S or Bluetooth 4-enabled Android phone, which then displays the information in an app.
Unlike most such sensors, it’s capable of tracking single degrees of rotation on the wheel, which means that instead of tracking a magnet each time it comes back around, it tracks it on the way around as well. This makes it a lot more accurate, and opens up for its use in professional situations. Using a 3-axis acceleration it can also measure slope. All in all it can measure speed, acceleration, cadence, distance, grade of slope, and power.
There was a very limited $99 pledge option which is now sold out, leaving current backers having to pay $149 for the sensor. That reward is also limited, with the next tier up being $179. That’s not exactly cheap as far as what I’m used to paying for a bike computer, but then again, I can’t appreciate the accuracy of this in professional situations. I certainly wouldn’t mind having such a sensor on my bicycle, though I have to point out that strapping a phone to a bicycle can be a very bad idea if you do any kind of off roading. You don’t have to look long to find examples of devices having been shook to death because of such use.