inSSIDer - inSSIDer Essential makes it easy to maintain small business WiFi.
OpenWiFiSpots - Hotspot location app
NetSpot - NetSpot is a free app for wireless site surveys, Wi-Fi analysis, and troubleshooting
Wi-Fi Space - Hotspot location app
Wifi Analyzer - Wifi Analyzer is a handy tool which helps you to select a better channel for your wireless router.
pttrns - iPhone and iPad user interface patterns