MIWIFI by Xiaomi - Wifi router beta with a twist: you build it yourself
inSSIDer - inSSIDer Essential makes it easy to maintain small business WiFi.
Velop - Whole-home mesh Wi-Fi by Linksys
NetSpot - NetSpot is a free app for wireless site surveys, Wi-Fi analysis, and troubleshooting
Wifi Porter - Connect guests to your network quickly
Homedale - With Homedale you can search for Wi-Fi / WLAN Access Points and monitor their signal strength.