Examine source code of Advanced Twitter filters

{
  "manifest_version": 2,
  "name": "Advanced Twitter filters",
  "version": "1.3",
  "description": "allows to filter text-only tweets on a per-user basis",
  "icons": {
    "128": "icon.png"
  },
  "homepage_url": "https://github.com/erraineon/twitter-morefilter",
  "permissions": [
    "storage",
    "tabs",
    "webNavigation"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": false
  },
  "content_scripts": [
    {
      "matches": [
        "https://twitter.com/*"
      ],
      "js": [
        "contentscript.js"
      ],
      "run_at": "document_start"
    }
  ]
}