Hi, Twitter.com doesn't have these, I literally checked like 20 seconds back :)

- Undo tweet, you get time to discard/re-send last sent tweet - Analytics, you get stats of your tweets so you know which tweets are working and to increase engagement - Quick media preview, preview photos/videos in feeds in full aspect ratio quickly on hover, Twitter.com is still trying to fix the issue :D - Reader mode for links, my personal favorite, links in your timeline can be viewed in a beautiful reader view in the app itself - Save links for later