I don’t know why they make it so mysterious to find, but there is a really nifty wi-fi scanner built into Mac since (as I recall) Mountain Lion that will let you easily scan the wifi spectra for what is in your area. This is mostly useful as a way to maximize the perf of your wireless network by getting on channels not used by your neighbors. Personally, I haven’t had great luck using the “auto” setting for that.
Anyways, if you search, you’ll find a lot of articles on how to get to it, saying to open Wireless Diagnostics (Option-Click on the Wi-Fi icon in your menu bar; it’s at the bottom). Then, the articles say, ignore the wizard and press CMD+N to open the cool scanner tool. Well, good luck with that on Mavericks. 🙂 And good luck finding anything telling you to do anything different.
That’s why I’m writing this article, because you might otherwise think the Wi-Fi scanner had been removed from Mac, but no, they just changed how you get to it. A little menu spelunking reveals under the Window menu that there is an “Assistant” and a “Utilities” window. If you click Utilities, you will find what you are looking for.
You can also press CMD+2 to open it.
What is even cooler is that after you click Scan Now, it does the analysis for ya and recommends channels for the different bands. Nice.
Anyhoo, I always forget this stuff in between uses, so I wanted to write it down. Maybe others will find it useful, too. No need to buy any special apps–just use the built-in one. If you can find it!