Astri is a multitool written in python, it contains tools with different applications and is an excellent resource to find reliable sites of different types.

Frost Network Simulation Tool is a subscription-based ($8/month) Discord-delivered Windows suite for network emulation, packet analysis, and diagnostics. It offers Windivert-based latency, loss, duplication, corruption, filters, UDP generation, save/load profiles, an IP sniffer with geolocation, speed tests, pingers, port scanning, and traceroute.