If the Finger-Ink app closes for any reason during form filling (e.g. the home button gets pressed, the iPad falls asleep, or, dare I say it, the app crashes 😨), there's an auto-save mechanism in place that will save your (or rather your patient's) progress in the form.
When you open the app again, it will ask for your admin passcode in order to continue with the form. Simply enter in your passcode and the form will pick up right where it left off.
Here it is in action simulating a crash by "force closing" it:
By the way, if you don't want to continue with the form you can learn how to exit the form here.