Display nearby WiFi access points in the palm of your hand.
When I arrive at the site of a client who needs WiFi help, my first step is to survey the site for existing WiFi RF signals. I usually use NetStumbler on a netbook. Now I can perform a similar survey on my Android phone, which I carry in my pocket.
I’ve tried Meraki WiFi Stumbler and Wigle WiFi Wardriver. For this survey application, I prefer Meraki WiFi Stumbler. It provides a bar chart with WiFi channel numbers on the x-axis and wireless access points’ (identified by their SSIDs) signal strengths in dB on the y-axis. It seems to be less sensitive and scan slower than Wigle, but its display is ideal for a quick WiFi site survey. Wigle is more comprehensive and an impressive piece of work, but its added features aren’t needed for ad-hoc WiFi site surveys.
My headline calls this hardware/software system a “spectrum analyzer”. That’s not strictly true. A full-blown spectrum analyzer displays all of a signal’s blemishes: distortion products, noise sidebands, harmonics, etc. The graph displayed by Meraki is merely a symbolic representation of nearby WiFi signals, after filtering out their blemishes. In most cases, it’s all the information that I need.
Oct 22: I’ve begun to use WiEye. I like it. Its display is simple, provides excellent resolution, and quick response. I found it in the Google Play Store.