dads.cool supports local-only posts. These are great for content you think only dads should see.

A post marked as local-only will appear only to dads.cool users.

A followers-only post marked as local-only will appear only to dads.cool users who follow you.

If you uncheck "Allow my posts to reach other instances by default" in Preferences - Other, your posts from any source—including apps—will be local by default.