The app crashes for you trying to render a specific PDF document. You should be able to long press the app icon on your home screen and select "My Library", the app should then open normally and show items in your library. Let me know if that works for you.

Also, if you could remember which document you had last opened before the app started crashing, try opening the same document and see if you crash again. If you do, please send us the document to support@zotero.org so that we can try to fix the problem. Thanks!