DNS Report : The free, thorough report on the DNS for your domain
OpenDNS : The safest, smartest, fastest and most reliable DNS on the planet.
Gixy : Gixy is a tool to analyze Nginx configuration. The main goal of Gixy is to prevent security misconfiguration and automate flaw detection.
Syncthing : Syncthing is a continuous file synchronization program. It synchronizes files between two or more computers in real time, safely protected from prying...
Kali Linux : Penetration Testing Linux OS containing tools to test the security of system or a network.