On: What are the best online activities to do with fri...

[kentich]

There's nothing wrong letting people know about a useful tool that they can take advantage of. It is not a promotion. It is distribution.

[jaden → kentich]

From the guidelines

> Please don't use HN primarily for promotion. It's ok to post your own stuff part of the time, but the primary use of the site should be for curiosity.

[xu3u32 → kentich]

At least be clear about the self-promotion.

[tailspin2019 → xu3u32]

Yes, to me this is the only thing objectionable about the GP’s comment.

Just be transparent. If anything it might provoke further interest and discussion too.