With Threema 2.9.0 for iOS, message previews can be displayed in push notifications. This feature requires iOS 10 or later and can be enabled/disabled in Settings > Notifications > Push Notifications. When receiving a push notification, Threema first downloads the corresponding message from the Threema server and decrypts it in the background in order to display a preview of the message content. To learn more about the security implications of enabling this setting, please refer to this FAQ article.
If message preview is enabled, push notifications are interactive, allowing you to reply to (or agree/disagree with) a message right from the push notification – even on the Apple Watch.
Besides other improvements, the 2.9.0 update also provides a handy date/time picker for easy scheduling of appointments in polls. Visit the changelog.