NIXStats - SaaS monitoring tool for window/linux servers and websites. Think up-time robot but with more features.
The Security Checklist - The Practical Security Checklist for Web Developers
SolarWinds System Management - Performance monitoring and management for applications, Websites, servers, storage arrays and virtual infrastructure.
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.
Nodeping - NodePing Server Monitoring and Web Site Monitoring. Simple but powerful Internet service monitoring.
WordPress Security Scanner - Check if your WordPress site has known vulnerabilities