Question

I want show release notes (open new tab with my site or webkit notification) when my extension auto updated. How I can do this?
Please help me.

Answer 1

You can save your extension version number in localStorage and check on extension startup if current extension version matches the one that is written in localStorage, if it doesn’t it has been updated and you can open new tab.

background page:

window.addEventListener("load", function()
{
    var ver = "1.0.0";
    if (localStorage.ver !== ver)
    {
        if (localStorage.ver)
        {
            // it was updated
            chrome.tabs.create({url:"YOUR_URL"});
        }
        localStorage.ver = ver;
    }
}, false);