If you work in the building trade or are a DIY enthusiast then here is an app that might make your life easier.
Bubble is a free spirit level for your Android phone. Simply install the app on your phone and you've always got a way to measure if a surface is straight or not. You can use any side of the phone to measure the angle of a surface. Just rest the edge of the phone against the surface and keep an eye on the bubble. You can also measure a surface by laying your phone face up on the surface. If the bubble is dead in the center of the gage then the surface is flat. If it's not flat then the position of the bubble to the left of right of the center will indicate how off it is.
Before you start, you should calibrate Bubble so that the readings are accurate. This is very easy and is achieved merely by resting each side of your phone against a surface you know is straight then pressing the Calibrate button.
There are a number of settings you can tweak to make Bubble more effective. For instance, you can choose to show the numeric value of the angle, enable beeps or buzzers that play when a surface is level, or switch to a black background.
I have few criticisms of Bubble, other than that it would've been good to be able to change the color of the liquid in the spirit level, and maybe choose from some more background.
But if you want to measure the angle of a surface without rushing out to the hardware store, Bubble makes for a reliable and easy solution.
- v2.0.1: try to avoid SD card installation bug on certain phones like the Droid Fix orientation bug on tablets such as the Galaxy Tab 10.1 Improved Honeycomb support Add new option to show high-precision angle with one decimal place Add support for installing to SD card Add new option to lock the level's orientation Updated text-to-speech support Improved beep sound Clicking dpad/trackball now toggles the lock Now shows confirmation dialog before calibrating