My dad suggested that it might be an anchor for a swing set, so the kids can't tip it over.

I personally found that https://taiga.io hits a sweet spot for me. It's a beautiful app. Not too simple but robust enough to configure. There's at least one good mobile client out there too.

Probably not Google Cloud Domains, I'm in the middle of a transition to GCP, and this is total overkill, while at the same time not having the convenience I was hoping to find. I've got to deploy a whole custom cloud function to replace the Synthetic DNS record for my dynamic DNS.