Batboard

This is actually a cool tool to have. It's an app you can get at Google Play, and it's free.

What started off as a college physics problem, turned into an engineering project, and then an art project with installation, cheese, sparkling water, and everything.

Newcastle Univ GB made an arduino device to help temperature map wifi rssi in a space. Someone took it a step further making a droid app. Kirlian Device Mobile is free to download, and a no-brainer to use. It is not super fast. It takes a moment for it to change colors and tone as rssi fluctuates. But, if you're patient, it can tell you how good or bad signal strength is in a room with your smartphone rather than a clunky piece of test equipment.

So, break out your Geek flag, wave it high, serve some cheese, visualize the ether, occupy the hertzian space, and look good doing it too because you just committed art.

Sweet! I can think of the perfect application for this in SAR

It is a simple tool to use. Obviously, it is limited by your phone's wifi card. I wouldn't call the displayed rssi a calibrated result, but it is what that phone is receiving. And it doesn't guarantee reciprocity. ie: how strong your phone is received by the AP. But, the immediacy of this tool helps you quickly earball a location as good/bad pass/fail for a given AP. If your device has an external antenna, or if the AP has adjustable antenna(s), you can find the best place to put them to achieve coverage in a room.