Thanks for the report. Does this happen every time you launch the app, or did it happen only once? In the former case, can you tap and hold the app icon, and select the "My Library" action.
I got a similar problem. Since the most recent update, zotero on iOS (specifically on the iPad) crashes every few minutes (sometimes even in a matter of a few seconds.
https://www.zotero.org/support/beta_builds#zotero_for_ios_beta