Examine source code of It's Media!

{
  "manifest_version": 2,
  "name": "It's Media!",
  "version": "1.0",
  "description": "Changes twitter's \"Media\" tab's label into \"It's Media!\"",
  "icons": {
    "48": "icons/media-48.png",
    "96": "icons/media-96.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.twitter.com/*"
      ],
      "js": [
        "replaceLabel.js"
      ]
    }
  ]
}