Examine source code of Window Sill

{
  "manifest_version": 2,
  "name": "Window Sill",
  "author": "Kevin Crane",
  "homepage_url": "https://github.com/kevincrane/windowsill",
  "description": "Sync your tabs in one Firefox window and have them waiting for you seamlessly on your other devices",
  "version": "0.2.2",
  "permissions": [
    "storage",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{cd8c8638-7f15-476c-8a8a-216cc125e07b}"
    }
  },
  "background": {
    "page": "src/background/background.html",
    "persistent": true
  },
  "browser_action": {
    "default_icon": {
      "48": "icons/icon48.png",
      "96": "icons/icon96.png"
    },
    "default_popup": "src/popup/popup.html",
    "default_title": "Window Sill"
  },
  "icons": {
    "48": "icons/icon48.png",
    "96": "icons/icon96.png"
  },
  "content_security_policy": "script-src 'self'; object-src 'self'"
}