Protonmail groups subject lines of your emails within a real time push notification
Protonmail is a privacy-centric email provider and has apps for iOS, Android alongside a web app. In this example, Protonmail sent a push notification of grouped emails with their subject lines to give you a quick glimpse of your emails in real time.
Why we think this push notification is good:
The curation and grouping together of look alike emails delivered in this programmatic push notification keeps their users in the loop of any important emails without you having to open the app. In this case, it had to do with stock orders being filled.