Please note, re-installing means that all of your bookmarks and any cached Spritz data will also be deleted.
Make sure that you sync all of your books in your ReadMe! library first!
To delete the app, just hold on the ReadMe! icon until it starts to wiggle and you see the Uninstall-trashcan at the top, drag the icon into it and confirm the removal.
Open up GooglePlay on your device and install ReadMe! again.
To get your books back to your ReadMe! library:
Start up the app, login to your account and synced books should show possible downloads in your library.