manifest.json

{
  "name": "Prrrowser",
  "description": "Browser extension that replaces images with similar images showing cats",
  "version": "0.4",
  "manifest_version": 2,
  "applications": {
    "gecko": {
      "id": "{2223e174-ae31-4b4c-a562-ae61043c947a}"
    }
  },
  "icons": {
    "16": "img/icon16.png",
    "48": "img/icon48.png",
    "128": "img/icon128.png"
  },
  "browser_action": {
    "default_icon": {
      "16": "img/icon16.png",
      "48": "img/icon48.png",
      "128": "img/icon128.png"
    }
  },
  "permissions": [
    "storage",
    "contextMenus",
    "tabs",
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "background": {
    "scripts": ["background.js"]
  },
  "content_scripts": [
    {
      "matches": ["<all_urls>"],
      "all_frames": true,
      "match_about_blank": true,
      "run_at": "document_start",
      "js": ["content.js"]
    }
  ],
  "options_ui": {
    "page": "options.html",
    "chrome_style": true
  }
}