The iPhone has a ridiculous amount of uses outside of a phone.  It was only a matter of time until someone came up with an app to check the accuracy of your watch.  Kello has done an good job of utilizing an iPhone and its original headset as the basis for their Mechanical Watch Analyzer.

The app is listed on the iTunes store for $8.99USD.  A little steep but considering that there is no other equipment to buy, its not all that bad.  The bad news is that it is not recommended for the iPhone 3G or iPod 2G.  But from what I hear, they are working on that problem currently.

So how does it work
Kello listens to your watch beat using the iPhone headset.  All you have to do is place the microphone piece against the back case of a mechanical watch.  Its recommended to sandwich the mic between the watch on the top, along with a soft and flat surface on the bottom.  This will allow all for a more crisp sound.

Once you have this setup you can simply hit the START button on the bottom of the app, and as long as you are in a quiet room, Kello will automatically figure out the frequency of your watch.  I found this process to be very quick.

Now the next part takes some time.  You really have to give it a few minutes to listen before it starts to level off in its rating of accuracy.  The slider at the bottom is key.  You are instructed to keep the curves on the readout to a peak instead of letting them flatten out on top.  I asked the developer if the goal of the peaks was supposed to be as high or low, they instructed to keep the peaks as low as possible.

I tested was a Seagull TY3620 which was tested on a TYMC a few months ago to be +2 seconds per day, and Kello bounced between +2.8 and +0.9 seconds per day, pretty close.

Microphone
Some users have recommended using different microphones to get the accuracy up.  But a really cool project is one that was recommended by the developer to me.  Although it looks like it will take a bit of skill, www.flynwill.com has a neat project to create purpose built watch microphone.  If anyone happens to give this a try please post in the comments section.

Overall
Kello is a very interesting application that I think is off to a great start.  Its utilizing equipment that really wasn’t really intended for watch use and seems to be doing a great job.  I asked what was next for Kello and they are currently working on updates and more features to the application.  Over time I expect to see it get more accurate.  This is only the first review of Kello from RWR.  As the app gets major updates we will post reviews on what’s new and how its coming along.  In the meantime you can check out their site.