Since you've only been a member of the Community for a few days, let me explain my vote to close for being off-topic. Meta Math.SE is the place to discuss the software that powers the Math.SE site, and to discuss issues like community moderation that affect the operation of the site (including new feature requests, creation of tags, etc.). General math-related software such as you describe is off-topic. Moreover it does not seem to fit into a Q&A format so much as to be asking for the attention of the Community. It is conceivable your work might address a Question that someone else posed. — hardmath 12 hours ago

Hi, thanks for your comment. I made a similar post, comparing to this one: math.meta.stackexchange.com/questions/24978/… so, I would like to understand why Approach0 is not considered off-topic too. — Flavio Gonzaga 10 hours ago

A short answer is that the author of Approach0 (with years of community membership) tailored that software to perceived shortcomings of site search on Math.SE specifically (excluding even MathOverflow as I understand it). Your software on the other hand seems to cast a wide net. I don't mean to discourage your efforts, but the purpose of the "questions" posted on Meta Math.SE are not for general promotion of mathematics related projects. You might try your luck with the thread Community Promotion Ads -- 2019 — hardmath 9 hours ago

Thanks for your comment Martin. We'll consider to submit SearchOnMath to Promotion Ads. :) — Flavio Gonzaga 12 hours ago