WiFi Analyzer Apps

Here is a collection of some links to apps that enable you to analyze and troubleshoot your WiFi configuration and coverage at a given site.

iOS

Network Analyzer - wifi scanner, speed test, tools
For iOS devices, but does not have all the WiFi details that are available on other platforms

Mac OS
7 Best Wifi Analyzers for Mac OS

Windows and Mac
9 free Wi-Fi stumbling and surveying tools
Slides 3 and 9 are Mac apps

Android
8 Best WiFi Analyzer And WiFi Scanner Apps For Android

Linux

• Kismet Wireless
• LinSSD
• Wavemon
• Network manager command line interface: nmcli d wifi
• Wireless LAN Sniffer Applications and Scanners for Linux
  -- a long list that includes some of the above

Also see:
How to Find the Best Wi-Fi Channel for Your Router on Any Operating System