KEYCHEST is described as 'Web and intranet HTTPS/TLS monitoring with API Setup and Forget - KEYCHEST discovers and audits new HTTPS certificates as they are created using CT Logs All Information In One Place - weekly reports, online dashbard, instant audits, real-time updates Internal Networks -'. There are three alternatives to KEYCHEST, not only websites but also apps for Windows and Linux. The best alternative is DigiCert Certificate Inspector, which is free. Other great sites and apps similar to KEYCHEST are Facebook Certificate Transparency Monitoring (Free) and GlobalSign Certificate Inventory Tool (Free).
Digicert’s Certificate Inspector scans the user’s network detecting all certificates in use, their configuration and implementation, and then displays the results in an intuitive and interactive dashboard.
Certificate Transparency is an open framework to log, audit and monitor all publicly-trusted TLS certificates on the Internet. This tool lets you search for certificates issued for a given domain. Subscribe to email updates to be alerted when new certificates are issued.