Dual Level: It keeps me balanced.

Games are great, social networking apps are useful, but things like Speedometer, Light, and  Dual Level, by Geometry, use the iPhone and iPod Touch in interesting ways to make apps that are useful in everyday life, not just in cyberspace. It's this kind of outside-of-the-box thinking we need to overcome the obstacles we face as a global community, as a species, and as individuals.

HAL9000 braved a wheelchair ramp to take this screenshot.

So, as you can see, there is a lot riding on whether or not Dual Level delivers the goods.  The fate of humanity rests on its bubbly accuracy.

There are, of course, multiple level apps on the iTunes store; I chose this one because it is--as you know by the name--dual leveled!

Here is the complicated review:  It works, and it works fairly well.

Calibrating is easy: just set it down on a level surface and hit the calibrate button.  The app is very stable, with the bubbles reacting in a very realistic way.

The degree readout bugs out when the device is lay flat on its back.

However, there is a bug in the "degree" measurement in the middle.  If the phone is laid down flat on its back, the degree readout doesn't work.  The only way to determine the degree of your incline is to balance the phone on its edge and tilt back and forth.  Of course, with the oh-so-ergonomic sides of the iPhone being all smooth and curvy, balancing the device on-edge is almost impossible.  The developers should make the readout work with the phone laid on its back.

Overall, Dual Level does its job with little fanfare.  The app is well worth the space it takes up on your screen, and it's priced right at $0.99.  Also available is Dual Level Pro, which allows you to "rotate the vials", displays angles to one tenth of one degree, and allows you to "compare any angle you want". For $1.99, though, it's hard to decide if I shouldn't just make a run to the hardware store.