"A dashboard interface would be great for sending push notifications, but most importantly a notification service that integrates with my event analytics is what I'd look for. I'd like to be able to automatically target notifications to certain segments of users.
For instance, if a user / device hasn't opened my app in 2 weeks, it'd be great if I could send them a bump. Or target certain regions for promotions, etc.
One frustration I've had is the overwhelming variety in mobile analytics and push notification services available. It seems like a new one pops up every week, and I tend to prefer the more established services like Mixpanel, or ones with significant backing / eco-system like Firebase Analytics + FCM (as it gains momentum).
An Expo service would be useful, especially if it seamlessly integrates with my Expo apps, though it'd be nice if could "play nice" with other more robust platforms like Mixpanel or the Firebase ecosystem."