Calendar notifications are surprisingly easy to miss.

They get buried under other alerts, dismissed accidentally, or simply aren’t loud enough to pull you out of what you're doing. I've missed meetings because of it.

So I built OnTimer, an iPhone app that turns calendar events into persistent alerts that are hard to ignore.

It connects to Google Calendar and Microsoft 365 and can also generate Time-to-Leave alerts based on travel time and traffic for events with a location.

Curious if others have run into this problem or have ideas for improving it.