Note 9 Tips

1. Double tap the recents button on your nav bar to jump directly to the previously used app. 
2. Customize nav bar, notification bar, recent apps, etc. with Good Lock from the Galaxy app store.
3. Secure Folder - you can set up separate apps logged into different accounts with different fingerprints, etc.

http://www.androidbeat.com/2018/09/best-samsung-galaxy-note-9-tips-tricks/