There are a number of free utilities (wifi anlayzer/scanner/inspector) available to assist with managing WIFI configuration. They allow one to find all wireless access points in range, check signal strength, choose a more optimal channel, show security strength and detect rogue devices. Nothing for iOS – it would appear that this type of tool won’t be approved by the App Store.
For WIndows, Mac OSX and Android
XIRRUS WI-FI INSPECTOR
For WIndows. Also offer a Desktop gadget.