Not the best start.
Response from developer
Hello, I am sorry this happened. The first thing I ask users to look at is what date they entered for the due date. Otherwise, when this happens, one possibility is that the phone is older or out of memory. However, if you send your specifications to helloamber@gmail.com, I can look into it and see what's going on. In the meantime, if desired, you can request a refund for the app. From the App Store on iPhone or iPad, tap the Apps section and select Request a Refund at the bottom of the page.