Examine source code of Focuzr

{
  "name": "Focuzr",
  "description": "Block time-wasting websites for a selected time and focus on more important things.",
  "version": "2.0.1resigned1",
  "background": {
    "scripts": [
      "blocker.js",
      "background.js"
    ]
  },
  "permissions": [
    "tabs",
    "contextMenus",
    "history",
    "http://*/*",
    "https://*/*"
  ],
  "icons": {
    "16": "images/icon_16.png",
    "48": "images/icon_48.png",
    "128": "images/icon_128.png"
  },
  "browser_action": {
    "default_title": "Focuzr",
    "default_icon": {
      "19": "images/icon_19.png",
      "38": "images/icon_38.png"
    },
    "default_popup": "popup.html"
  },
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "{bcee1aa0-92ea-4c73-9315-7dd516bf895e}"
    }
  }
}