Using my iPod Touch, I’ve sampled a few Wi-Fi apps from the App Store. Generally, the built-in Wi-Fi settings (under Settings) are good enough. The iPhone OS gets the job done. However, it only displays a limited number of networks, and with little detail. From my experience, only the closest networks are displayed.
I dabbled with WifiTrak a while ago, but when iPhone OS 3.0 was released, the version of WifiTrak that I had wasn’t compatible. I removed the app and didn’t think about it after that.
WiFiFoFum is my latest choice to sniff out Wi-Fi networks. It is very detailed, showing the channel of each network, security method, signal strength, and more. If you want to gather info about networks in the area, it is the one to use. The app even has a radar which displays on a radar screen the location of each network source. I don’t know how accurate the radar is, but in my simple tests, it did a good job.
One benefit of using an app such as WiFiFoFum is being able to see the channel number of each network within the area. I realized that my own home network was using channel 6, as well was nearly ever other network within reach. I changed my channel to 8 to avoid any potential interference that may exist.