Voilà!

manifest.json

{
  "update_url": "https://clients2.google.com/service/update2/crx",
  "name": "Voilà!",
  "version": "0.1",
  "manifest_version": 2,
  "description": "Show the pictures of a given profile",
  "author": "João Órfão",
  "browser_action": {
    "default_icon": "icon48.png",
    "icons": {
      "16": "icon16.png",
      "48": "icon48.png",
      "128": "icon128.png"
    },
    "default_popup": "popup.html"
  },
  "permissions": [
    "tabs",
    "<all_urls>"
  ]
}