Now here's what I'd like: The opposite API for users (i.e. not developers/companies) which allows me – the user – to collect and handle (and prioritize!) all my notifications across all communication channels, whether it's "Your order got shipped" emails by Amazon, "Someone commented on your post" notifications on Facebook/Instagram, Slack reminders, Office 365 calendar notifications, …
Android notification manager is more advanced here. They force apps to separate their notifications by their nature so you can disable some of them. iOS is a bit too broad here. It’s a place where they have been copying Android for years but keep lagging for reasons I don’t grasp.
Well, "force" is a bit of a misnomer here. More like they allow apps to categorize their notifications. The result is exactly what you expect: some apps don't categorize notifications at all, and others (including Google ones) do it in a way that's misleading or designed to make the mechanism useless. There is a big conflict of interest here: the notifications users want to shut off the most are exactly the same ones the vendors want displayed the most.
The missing ingredient here is Google punishing bad notification categorization in some way (e.g. by diminished ranking in the Play Store, or failing the review process), but seeing how Google itself doesn't isn't too keen on clear categorization in their own apps, I'm not holding out much hope.
If only applications sent their notifications through e-mail.
I particularly miss the times when Facebook would send notifications to your e-mail, with full content included, within minutes to hours of an event, if you happened to be logged out from the service. This was a neat way of reading chat messages without making the sender aware you've read them (that was before the whole thing got separated out to become Messenger).
EDIT: one major benefit of e-mail as notification channel is that a typical non-ISP personal mailbox has practically infinite storage and a sensible search mechanism, giving you historizing/archiving for free.
That's a nightmare for a user or even the sass provider itself. User has to link every service he signs up for to this sass service. The sass provider must know every type of notification of every software on earth.
Or, you're thinking of notification settings on iOS and Android(You can also select which type of notification channels u want to mute).
or notification settings on the individual sites.
I can see from the docs that what I read as in-app notifications, is actually the notification feed rather than mobile in-app notifications (to make it feature complete, similar to Onesignal). Looks really promising and will follow this as it develops!
For now we only support a react ,vue, angular and web component. So no react native component at the moment. But you can always consume the react library with the provided hooks and implement your own UI using the API.