Different things happen to apps when they get acquired. One of the scenarios is the technology and team behind the purchased company gets absorbed into products developed by the one who purchased them. And that is what’ll happen to Sunrise. The calendar app bought by Microsoft last year will be officially shutting its doors on August 31st. They are already pulling the app from the app stores and no new features or bug fixes will be heading its way. After the end of August, the app will stop working altogether.
The Sunrise team says they are busy working on the Outlook app for iOS and Android. So if you use this app, you should be seeing some Sunrise features show up there.
Source: Sunrise