Choose OnTimer if
People whose meetings, appointments, and flights already live in Apple, Google, or Outlook calendars and should become alarms automatically.
Calendar alarm comparison
OnTimer vs Due
Choose OnTimer when the schedule already lives in your calendar and you do not want to create or maintain reminders by hand. Choose Due when you want to create individual reminders and have overdue notifications repeat until you complete, reschedule, or disable them.
Last reviewed October 13, 2026
Choose Due if
People who want fast manual reminders, repeating overdue nudges, and reusable countdown timers for tasks and errands.
Key differences
| What to compare | OnTimer | Due |
|---|---|---|
| Source of truth | Your existing calendar | Reminders created in Due |
| Setup | Calendar events become alarms automatically | Create each reminder or timer |
| Persistence | Alarm remains active until dismissed | Auto Snooze repeats overdue reminder notifications |
| Travel timing | Time To Leave and Time To Fly | Not described on the reviewed product page |
| Platforms | iPhone | iPhone, iPad, Apple Watch, and Mac |
Keep your calendar. Add an alarm layer.
OnTimer is free for one calendar provider on iPhone.