https://domain-locker.com/

I built Domain Locker to keep track of all my domain names in one place. It shows registrar, expiry, DNS, SSL, subdomains, and more - plus alerts you before something important changes or expires.

It's free and open source, can either be used at domain-locker.com, or self-hosted with Docker. The source is on GitHub at https://github.com/lissy93/domain-locker

Would love to hear your thoughts, feedback, or ideas!