Your books are deleted when you log out for two reasons:
In case another user logs in after you. For that reason the stored files are removed to save phone memory and in readiness for another user's profile
- this is a hard reset on the app in case of any issue with your profile, much in the same way that you would log out and back in again to solve a general computer issue.
Once you have logged back in, it takes just a second to re-download each book. All previously downloaded books can be found in My Books.
Unless you need to, we recommend that you remain logged in.