I've found the combination of Etar (https://f-droid.org/en/packages/ws.xsoh.etar/ https://f-droid.org/en/packages/ws.xsoh.etar/) and Calendar Notifications (htt

I've found the combination of Etar (https://f-droid.org/en/packages/ws.xsoh.etar/ https://f-droid.org/en/packages/ws.xsoh.etar/) and Calendar Notifications (https://f-droid.org/en/packages/com.github.quarck.calnotify/ https://f-droid.org/en/packages/com.github.quarck.calnotify/) on my Android to work really well for tracking events and creating reminders. That combo, however, really isn't going to scale well for 'business' reminders.