PingPing - A simple tool to monitor your website and SSL
WebGazer - Monitor your website's availability with WebGazer, review its performance and get instant notifications when your website goes down. No installation required and free plan available.
Flywheel - WordPress hosting and management built for designers and agencies.
Oh Dear! - Website monitoring, without the hassle
haveibeenexpired - No more expired SSL certificates
Freshworks - Delight your customers, from wherever you are