Examine source code of InstaBlock

{
  "manifest_version": 2,
  "name": "InstaBlocker",
  "description": "Block addicting Instagram features. Take back your time.",
  "version": "3.0.4",
  "icons": {
    "16": "icon/16.png",
    "32": "icon/32.png",
    "48": "icon/48.png",
    "128": "icon/128.png"
  },
  "permissions": [
    "storage",
    "declarativeNetRequest",
    "*://*.instagram.com/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "instablock@mohammadanwar.com"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "InstaBlocker",
    "default_popup": "popup.html"
  },
  "options_ui": {
    "page": "options.html"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.instagram.com/*"
      ],
      "run_at": "document_start",
      "js": [
        "content-scripts/content.js"
      ]
    }
  ]
}