WiFi Radar is a small GUI utility that can be used to scan the wireless networks in your neighborhood. It shows the available networks, their strength and the channel they are on. Using this information you can decide which channel you would like your wireless router to use. It can also be used to manage connections, though I prefer to use Ubuntu's default tool to do that.
It can be installed easily:
$ sudo apt install wifi-radar
Tried with: WiFi Radar 2.0.s08 and Ubuntu 14.04