Android app review: Bubble Level

There are times when you find yourself without the right tool for the job. Or maybe you have the right tool, but you can't find it (or get to it). But with the Bubble Level app for your Android device, at least you won't have to worry about finding a level when you need one.

This app lets your Android phone act as a spirit level. You can use any of the four sides of your phone, and a bubble level graphic will appear on the screen, showing whether the surface you are inspecting is level, plumb, or at an angle. The app will even display the degree of angle or incline.

You can also lay your phone flat on a surface and Bubble Level will become a 360 degree level, showing in which direction (if any) the surface is not level. There are portable pocket-sized levels you can stuff in a toolbag or even your pocket, but Bubble Level is with you anywhere your phone goes.  If you feel like it's not giving an accurate reading, you can recalibrate it at any time.

Calibrating or recalibrating the app is easy. Just place the phone on a known level surface and select Calibrate.  You can calibrate each side separately, in case your phone has a button sticking out on one side or a weirdly-shaped case, or something else causing a side to not be perfectly straight. Before any calibration, Bubble Level gave me fairly accurate readings; after calibrating it, it is almost as reliable as my Stanley Pro I-Beam level. Just make sure when you are using the app that the phone is at a perfect 90 degree angle (unless it's flat on its back) -- otherwise your readings will be off.  If you have an OtterBox or other protective case, you may want to remove it before using the level.

Unlike many free apps, Bubble Level is highly customizable. You can change the viscosity of the bubble, turn on eco mode to preserve battery life, enable orientation locking and even turn on sound effects so that the app plays a sound when the phone becomes level. There are no ads that pop up; the developer simply added a very unintrusive "Donate" link toward the bottom of the Preferences menu.

Bubble Level is available for free from the Android Market.  It is compatible with devices running Android version 1.6 or higher and it only takes up a measly 90 KB of space. This app has an average user rating of 4.2 out of 5, from over 66,000 users, and it's been downloaded and installed more than 11 million times.

(Originally posted on Helium.com, January 2014)