If your app starts crashing upon launch, go to the Settings app on iPad and turn ON Safe mode under the Noteshelf 2 app tab.
When you enable safe-mode, the app will not crash anymore upon start.
After it opens up normally again, kindly send us the following :
-Any book/pdf file that has been crashing the app every time when you access it
-In-app email from the support tab under the gear icon so we receive some diagnostics form your device
That’ll help us identify and fix these crashes. Thank you for helping us with this.