Bookstats will not continue operating in the near future. The app announcement cited serious health problems affecting the person who keeps the project running. No fixed shutdown date or export deadline was given, and nobody knows what will happen to the server data after a shutdown. If your library still lives in Bookstats, I would export it now rather than wait.
The question of alternatives also came up in the Reddit thread about the Bookstats shutdown and the Bookcrossing thread about alternatives. I personally pointed to LibrisLog because it can import Bookstats export files and is designed for people who want to keep control of their own library data. The source code is openly available on GitHub. That reply is what led to this migration guide.
I am the developer of LibrisLog, and I ran the migration myself using my own Bookstats export. It contained 178 book rows. The workflow is pleasantly […]