Are there any other good places (besides Reddit)

Unless you are an active long term personality in the relevant Reddit community, Redditors are likely to see your promotion as spam.

Youtube, a personal blog, and other pull-media are within your control.

afraid it’ll just disappear unnoticed

Building many more useful things is the best way to get people to notice your work. I mean if it will still be useful in five years, then you have time.

Or to put it another way, your favorite composer/muscian/band didn’t just make one song…and didnt only start practicing their instrument last week.

More importantly, in large part they do what they do for self-expression not just for fame. That makes it possible to cope with the statistical reality that nobody cares.

It would be unfortunate if this is the best work you ever did. Good luck.