The thing to do with articles you feel don't belong on Hacker News is to flag them. The name calling and gratuitous negativity are against the guidelines and end up discouraging submitters who might have something on-topic to share, and we don't want to miss those.

https://news.ycombinator.com/newsguidelines.html

please delete my account here.

There are no rules against submitting your own blog posts. As we know, it's quite common on HN. Though I have noticed personally that my blog posts get more activity here when submitted by others.

There are also no rules against plugging a product in a post. Again, it's extremely common on HN.

OP's user account was created 1339 days ago. I don't think his intention is suddenly to spam at all nor do I believe the post is "just a spam piece to advertise his app".

Are there any HN extensions/plugins that allow you to tag users? I can tag garbage authors on Reddit with RES so I know to avoid their articles, it'd be handy to do the same on HN.