inSSIDer

Download inSSIDer, MetaGeek's wireless network scanner, and you'll be able to improve your Wi-Fi by performing a quick Wi-Fi survey that helps you choose the best channel for your network. It will also display network security, existing network overlap, adjacent channel conflicts, and more.

features include:
Wi-Fi Scanner for 2.4 and 5 GHz bands, Wi-Fi Networks table with information about each access point your device can detect, Wi-Fi Channel Scoring, Wi-Fi Channel Graph for both 2.4 and 5 GHz, Wi-Fi tips and tricks, and no advertisements.