Appointment book with reminders that actually go off

The failure everyone has had

A missed appointment is rarely a scheduling problem. The appointment was in the app; the reminder simply never rang, because the phone decided the app was idle and put it to sleep. Certain Android skins are notorious for it.

The reminder path here is built around that reality: an exact alarm rather than a best-effort background job, an optional full-screen alert that takes over the screen the way a phone call does, and a check that the record still exists before anything rings — so a deleted appointment cannot come back to haunt you.

• A notification for a normal reminder
• A full-screen alarm for the appointment you must not miss
• 17 sounds, so the work alarm is distinguishable from the morning one
• Reminders keep working with no connection
• Deleting an appointment cancels its alarm properly

Planning the day, not just the alert

The daily view is the working screen: who is coming, at what time, and what they had last time — because the appointment is attached to the customer, not floating in a calendar. The weekly view is the planning screen, used when someone asks whether Thursday afternoon is free.

Instalment due dates can raise the same kind of reminder, which means the phone tells you when to call about money as well as when to open the shop.