Examine source code of Reading Mode Basic

{
  "manifest_version": 2,
  "name": "Reading Mode Basic",
  "version": "1.0",
  "description": "Reading Mode is extension Toggle any webpage into a cleaner reading mode.",
  "permissions": [],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "128": "images/reading-logo.png"
    }
  },
  "icons": {
    "128": "images/reading-logo.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{41b82ac3-d411-40e7-ba70-05b685b319f1}"
    }
  }
}