It’s very unlikely that your schedules or other settings have been affected.
From your computer or phone, visit app.rach.io , log in, select your controller and you should be able to view and change almost everything that you can do in the app. Assuming that your schedules are intact, and you can operate the controller (e.g. Quick Run), there should be no problem deleting and reinstalling the app on your phone. If the app still gives you trouble, just use app.rach.io instead (you can put a link on your home screen), until it gets fixed.
If app.rach.io shows your schedules gone or controller not working, contact Rachio support before messing with the app.