Can WitnessWork remind me when my report is ready to submit?

Yes. Go to Settings → Preferences → Plans and turn on Remind Me to Submit My Report, or tap Remind Me when the report screen offers it after you submit. On the 1st of each month you get a reminder at your Remind At time (9:00 AM unless you change it) that last month's report is ready. Tapping it opens that month's report, where you can review it and submit it with your usual method. WitnessWork never submits your report for you. There's no reminder for a month with nothing logged, or for a report you've already submitted from the report screen or marked as already submitted from the Home bell; submitting it after the reminder arrives clears it. Turning the setting on asks for notification permission, or opens your device settings if you've declined before. The reminder is worked out on your device from your own records and isn't sent anywhere. Each device schedules its own reminder, so open WitnessWork during the month to keep it current; if you submit on another device, open WitnessWork on this one so it knows. On Android, the system may deliver it a few minutes late to save battery. If it doesn't arrive, check that notifications are allowed for WitnessWork in your device settings (on Android, including its Reminders category) and that Focus or Do Not Disturb isn't silencing them. Last month's report is also listed in the Home bell until you submit it, even with notifications off. If it still doesn't work, report the problem from the Help Center without including names or other private details.