Examine source code of SaveTabs_

{
  "manifest_version": 2,
  "name": "SaveTabs",
  "version": "0.4resigned1",
  "description": "Save tabs of the current session and restore them next time.",
  "applications": {
    "gecko": {
      "id": "savetabs@t2dev.de"
    }
  },
  "browser_action": {
    "default_popup": "popup/choose_load_save.html"
  },
  "permissions": [
    "tabs",
    "storage"
  ]
}