Tweet collaborations will allow two individual user handles to be associated with a single tweet. This will be a more productive way of getting a message out there when working together, and removes the need to retweet.
This looks like a really promising feature. We believe that this will boost the engagement of tweets and reach new audiences - having benefits for both users.
Users can now create posts with reminders on Instagram, which people can receive notifications for. This is a valuable feature for capturing interest in a physical event, merch launch or new music.