I've definitely been missing meetings because I don't have a sound to distinguish this is an event reminder. This should register as a calendar app like Gmail does so can you can change it on IOS.

How is this still not a feature? I'm trying to go exclusively to Proton calendar, but the little chime isn't enough, and I've missed meetings because of it. I'd even like to see an alarm as a notification option where I have to dismiss it to make it stop.

I moved all my non-work related events and appointments over from google. Had I decided to go cold turkey I would have missed several appointments and events. My normal notification sounds is very mellow so, I can attend meetings w/o having to turn my sound or phone off (because I often forget to turn them back on afterwards).

I would love to completely drop google calendar and this is the one item that keeps me from getting rid of it.

It would be nice if there was a sound unique to Proton that is used to notify of a new email received - rather than the default phone notification sound. I use another private email service that has several notification sounds unique to the app that notifies of a new email being received in the inbox because I don't like the Proton Mail iPhone app not having the ability to change that feature.

This is important for me so I can make the calendar notifications more noticeable and attention-grabbing. On my Android phone, the sound for Proton Calendar notifications is very slight (a short and mild beep), and keep missing them..

Quite right. By defionition, calendar events are time- or day-specific, and thus have a high time sensitivity and priority.

In contrast, SMS and other instant messages are not time-sensitive, so it really is necessary to know which type you have just received.