A different way of letting users know that your Chrome extension or app has been installed/updated

event.js

chrome.runtime.onInstalled.addListener(function() {
  var options = {
    type: "basic",
    title: "Version " +
      chrome.runtime.getManifest().version +
      " installed",
    message: "Just thought you'd like to know that this extension is now installed!",
    iconUrl: "assets/icon_128.png"
  };
  
  // In a real extension or app, you'd examine the current version and
  // compare it to the last time you displayed the message.
  var shouldDisplayInstallationMessage = true;

  if (shouldDisplayInstallationMessage) {
    chrome.notifications.create("my_id", options, function(id) {
      console.log("created", id);
    });
  }
});

manifest.json

{
  "manifest_version": 2,
  "name": "Hello World",
  "version": "1.2.3.4",
  "icons": {
    "16": "assets/icon_16.png",
    "128": "assets/icon_128.png"
  },
  
  "permissions": [
    "notifications"
  ],
  
  "background": {
    "scripts": ["event.js"],
    "persistent": false
  }
}