Nmap - Nmap Free Security Scanner, Port Scanner, & Network Exploration Tool. Download open source software for Linux, Windows, UNIX, FreeBSD, etc.
Wifi Router Manager - Wifi Router Manager is a free-to-use network tool application that is providing the complete visibility of your wifi network from signal strength, security to IP addresses.
Angry IP Scanner - Open-source and cross-platform network scanner designed to be fast and simple to use
SelfishNet - Block anyone or any device from using your internet
Advanced IP Scanner - Advanced IP Scanner shows all network devices, gives you access to shared folders, and can even remotely switch computers off. Download it Free.
SoftPerfect WiFi Guard - Security of your Wi-Fi network for Windows, macOS and Linux