Examine source code of Monitorito

{
  "manifest_version": 2,
  "name": "Monitorito",
  "description": "This extension creates a real-time visualisation of your browsing activity",
  "version": "1.2resigned1",
  "browser_action": {
    "default_icon": "icon.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "16": "icon16.png",
    "32": "icon32.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "permissions": [
    "tabs",
    "webRequest",
    "http://*/",
    "https://*/",
    "webRequestBlocking",
    "storage"
  ],
  "id": "monitorito@github.io",
  "applications": {
    "gecko": {
      "id": "monitorito@github.io"
    }
  }
}