Examine source code of Reddit Repost Bot Tagger

{
  "manifest_version": 2,
  "name": "Reddit Karma Farming Bot Tagger",
  "version": "1.0.2",
  "description": "Displays the post-to-comment karma ratio for Reddit users next to their username",
  "author": "/u/bgroins",
  "homepage_url": "https://github.com/399iejijw9e29ejiwjljasd/reddit-repost-bot-tagger",
  "content_scripts": [
    {
      "matches": [
        "*://*.reddit.com/*"
      ],
      "js": [
        "main.js"
      ],
      "run_at": "document_end"
    }
  ],
  "permissions": [
    "*://*.reddit.com/*",
    "storage"
  ],
  "options_ui": {
    "page": "options.html",
    "browser_style": true
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{417a9f6c-faf9-4f91-94c9-049a38520242}"
    }
  }
}