Examine source code of Box Critters ModLoad

{
  "manifest_version": 2,
  "name": "Box Critters ModLoad",
  "version": "0.3.1",
  "applications": {
    "gecko": {
      "id": "bc-modload@boxcrittersmods.ga",
      "strict_min_version": "59.0a1"
    }
  },
  "description": "Easily load and manage Box Critters mods.",
  "icons": {
    "16": "icons/16px.png",
    "32": "icons/32px.png",
    "48": "icons/48px.png",
    "64": "icons/64px.png",
    "128": "icons/128px.png"
  },
  "permissions": [
    "tabs",
    "storage",
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "browser_action": {
    "default_icon": {
      "16": "icons/16px.png",
      "32": "icons/32px.png",
      "48": "icons/48px.png",
      "64": "icons/64px.png",
      "128": "icons/128px.png"
    },
    "default_title": "Box Critters ModLoad",
    "default_popup": "popup/index.html",
    "browser_style": true
  },
  "background": {
    "scripts": [
      "background/background.js"
    ]
  }
}