Sorry you had a bad experience with this extension. The extension was definitely designed to persist tabs after computer shutdown. It uses `localStorage` (https://developer.mozilla.org/en-US/docs/Web/API/Web_Storage_API) to save URLs for each tab. This is designed to "persist even when the browser is closed and reopened." This storage can be cleared through the browser settings or through another Javascript extension.

Feel free to file an issue (https://github.com/avbhatt/tabs/issues). If you include some more information with your issue I can try and replicate the issue on my end.