Do you understand what my project is about?

I like the idea. Personally I skipped past the video on my first skim of the page - and actually this is the nicest way to see how the product works, so I think you could add something to tempt people to watch the video immediately like "Here's how it works -->".

The video itself took about 3-5 minutes to play through for me because it was constantly buffering. I lost interest and gave up waiting. It looks like you're hosting the video yourself which may be the reason for it loading slowly? If I watch the video on your chrome extension page (the YouTube hosted version) then it plays all the way through with no buffering.

The big image at the bottom of the page (showing comments on the Sentry landing page) is the image that made me understand what the product is. I think this should be higher up the page. Personally I think step 1 of "how it works" could be much smaller, because step 2 is what I was looking for.

A couple of small grammatical issues:
"How does it works?" should be "How it works" or "How does it work?"
"Share the link and start gathering comment" should be "Share the link and start gathering comments"
"100 new pages by month" should be "100 new pages per month"

One more minor point - I didn't see the "Chrome" download link at first. I assumed "Install" from the line "Install the extension" was going to be a link to install it.

Best wishes for your product journey :-)

I understand what the video shows, but the landing page is full of grammar error. For example in the H1

Gather feedbacks on every pages your working on

should be instead

Gather feedback for every page you're working on

I put more feedback in a video on YouTube available here 📺