Examine source code of Scratch That

{
  "manifest_version": 2,
  "name": "Scratch That",
  "version": "1.0.5",
  "description": "Allows you to set filters which replace all instances of text on webpages.",
  "content_scripts": [
    {
      "matches": [
        "*://*/*"
      ],
      "js": [
        "replace/replace.js"
      ],
      "run_at": "document_start"
    }
  ],
  "permissions": [
    "storage"
  ],
  "browser_action": {
    "default_icon": "icons/scratch_that-64.png",
    "default_title": "Scratch That",
    "browser_style": true
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{07e611d9-b78a-4aa2-a1e6-f6baed36706a}"
    }
  }
}