https://sslping.com allows you to monitor your SSL/TLS certificates and security configuration easily for free. You'll receive an email if your certificates expire, or if a misconfiguration is detected.
You need node.js to use sslping-cli.
Install with npm install -g sslping-cli
This CLI allows you to import new servers to sslping, and to export a JSON document with all your servers and status.
Help: sslping-cli --help
Import example: sslping-cli -u me@mydomain -p myPassword import google.com facebook.com twitter.com
or cat servers.txt | xargs sslping-cli -u me@mydomain -p myPassword --quiet=true import > imported.csv
Export example: sslping-cli -u me@mydomain -p myPassword --quiet=true export > myservers.json
Note: JSON export format may change in the future (ie. this route is used by the react webapp)