I was surfing the iPhone application store the other day and came across this cool useful application. It uses the accelerometer sensor that is built into the iPhone and converts the data to be used as a spirit level. There is standard screen that has a regular level tool, then one that does X/Y.
I like it and it is handy when I am trying to see if a camera/digital back is level prior to taking a shot and looking at it on screen. It also has been accurate enough for my needs.
The reviews have been mixed on the store regarding this application because there is a similar application available for free vs $.99 in the iPhone development kit SDK. Honestly I do not have the time to play around with the SDK so it was worth the buck.
Direct link to the iTunes store for Level.
Here are a few images of the application:
