Find out the number of posts in the community on VK using the Chrome extension?

Question

Google Chrome

Hello, there are some sketches with crutches for the chrome extension, which works based on counting the number of posts in the community on VK, I want to know how to do everything correctly in the * .js extension file.
I also noticed one unpleasant thing, if the extension works, then the user is constantly online, even when he is not on the site, that is, tell me how you can do it so that if the user does not use VK (that is, he did not log out, but simply closed the tab), VK did not keep the status "Online" for the user.
Thank you for your attention.

Answer 1

If you are making an extension, I advise you to use the VK API, because if you use a script drop on the page, then the site will simply turn white, that is, there will simply be a white screen instead of the site. I don't know what it is connected with, maybe with adblock, or maybe something else. Another plus of the VK API is that when using it, the user is not online)
Of course, you can’t see the sketches?