Examine source code of Breathing

{
  "name": "Breathing",
  "description": "__MSG_extensionDescription__",
  "version": "0.0.1",
  "manifest_version": 2,
  "default_locale": "en",
  "permissions": [
    "storage"
  ],
  "options_ui": {
    "page": "public/options.html",
    "open_in_tab": true
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_action": {
    "default_popup": "public/index.html",
    "default_title": "__MSG_defaultTitle__",
    "default_icon": {
      "16": "public/icons/breathing_16.png",
      "32": "public/icons/breathing_32.png",
      "64": "public/icons/breathing_64.png"
    }
  },
  "icons": {
    "16": "public/icons/breathing_16.png",
    "32": "public/icons/breathing_32.png",
    "48": "public/icons/breathing_48.png",
    "128": "public/icons/breathing_128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{8e0dba24-ce3d-41e1-910b-e944bdc96e5d}"
    }
  }
}