Support
Something not working, or not behaving how you expected? Most of it is answered below. If the answer is not there, use the form and you will get a reply from a person.
Ask about CalDelta
Say what you did and what happened instead. Your iPhone model and iOS version usually save a round trip.
The list is empty and I have plenty of events
That is expected on the first day. CalDelta reports what has changed, not what is in your calendar, so on first launch it records everything already there as your starting point. Anything created in the last week shows up straight away; after that, add, move or delete an event and pull down to refresh, and it will appear.
Nothing is listed under my calendars
Open Settings inside the app and check which calendars are ticked. If none are ticked, CalDelta watches all of them. If the list is empty altogether, the account may not be on the phone yet. Add it in the iOS Settings app under Apps › Calendar › Accounts, then come back and pull to refresh. Google, Microsoft, iCloud and any other account iOS supports all work the same way, because CalDelta reads whatever iOS already has.
I did not get my daily notification
The notification is deliberately silent when nothing has changed: no changes, no notification. If something did change and nothing arrived, check that notifications are allowed for CalDelta in the iOS Settings app, and that the app has not been force-quit from the app switcher: iOS will not wake an app the user has swiped away. The digest arrives within a few minutes of the time you set, not exactly on the minute.
Changing the time, or turning it off
Tap the gear in the top corner and set "Notify me at". To stop notifications entirely, turn them off for CalDelta in the iOS Settings app; the app will tell the scheduler to forget your device.
Does removing a row delete the event?
No. Swiping a row away, or removing several at once, clears it from CalDelta's list only. CalDelta never creates, edits or deletes anything in your actual calendars.
Starting again
Settings › Reset baseline forgets every event CalDelta has seen and treats today's calendar as the new starting point. Nothing is deleted from your calendars.
Privacy
Your calendar never leaves your phone. The privacy policy sets out exactly what is and is not sent anywhere.
Still stuck
Use the form at the top of this page and say what you did and what happened instead. Include your iPhone model and iOS version if you can, since it usually saves a round trip.