Surge for Mac - Advanced Web Debugging Proxy for Mac & iOS
TinyWall - Lightweight and non-intrusive firewall
Charles Proxy - HTTP proxy / HTTP monitor / Reverse Proxy
simplewall - Simple tool to configure Windows Filtering Platform (WFP) which can configure network activity on...
HTTP Headers - HTTP Headers allows you to quickly see the HTTP header information for the current URL.
GlassWire - Visualize network activity in detail, get notified when new apps access the network, look out for...