Minimal FOSS Android homescreen widget:
Childs birthday:
1 year 3 months 18 days
- Default size 2×1; resizeable if the launcher allows it
- Per-widget label and start date
- Dark or light widgets
- Background opacity slider
- Count uses calendar years/months/days
- No network, no ads, no tracking
Tap the widget later to edit label/date/theme.
Allow "Alarms" for the widgets to update. On some devices, "unrestricted battery" might also be needed to stop Android from killing the app.