PuTTY - Popular free terminal application. Mostly used as an SSH client.
The Security Checklist - The Practical Security Checklist for Web Developers
MobaXterm - Enhanced terminal for Windows with X11 server, tabbed SSH client, network tools and much more
SafeBase - SafeBase is the interactive security portal to share your security posture, automate access to sensitive compliance information, and subscribe to vendor security program updates.
iTerm2 - A terminal emulator for macOS that does amazing things.
WordPress Security Scanner - Check if your WordPress site has known vulnerabilities