Customize Navigation Bar
You can customize navigation bar as you can do on the S8. You may want Back button on the left rather than right or charge the background color. Go to Settings > Display > Navigation bar, and you can change the layout of the navigation bar here as well as the background color.
Lock the Navigation bar
In an app, the navigation bar is likely to block the sight a little bit on the button. Every time it does, you can make it disappear by tapping the dot on the left end of the navigation bar. But, keep in mind that double-tap the dot make the bar locked at the bottom. It may come in handy for some apps going full screen. To unlock, make another double-tap.
Auto-rotate to landscape mode on home screen and app drawer
It’s a new feature on the S9 and S9+. As apps can rotate from portrait to landscape or vice versa, the S9 and S9+ can do that on the home screen and app drawer, too. It’s off by default. You need to go to Settings > Home Screen Settings, find Portrait mode only, and switch it off. Now, your home screen and app drawer auto-rotates depending how you hold the phone.
Quick access to the full settings page of WiFi, Sound, Power saving, etc.
It’s a tip and trick in common on Android devices. Instead of opening up the settings, tapping and tapping to reach the full and detailed settings page, just press and hold the icon, which appears when you swipe down from the top, and you can jump to the full and detailed settings page. It’s very useful for the settings you need to change often such as WiFi, Sound, Power savings, etc.
Stop Adding the shortcuts of new apps to the home screen
For those who have made the perfect home screen by selecting important apps and adding nice widgets, it’s annoying that it automatically add a shortcut to the home screen every time you install a new app. You can stop the phone from doing that. Go to Settings > Display > Home screen, find “add apps to home screen,” turn it off, and every app you install won’t be added to the home screen anymore.
Multi-window view
You can show and use two apps on display at the same time. Tap the Recent apps button and find the first app you want and tap the icon looking like two boxes at the top of that app card. The first app will stay in the top half of the screen. Next, you will select the second app from Recent apps or App list on the bottom of the screen. The second app will stay in the bottom half of the screen. You can change the sizes of the apps by dragging up or down the blue line between them. Please note that some apps always need a full screen and don’t work with this feature. I found it very handy with a combination of apps like Calendar, Doc, Calculator, Mail, and so on.
One-handed mode
Since the S8 and S8+, Samsung Galaxy smartphones have become a little taller. And, the displays got a lot taller. Consequently, it’s hard to reach the top when you hold the phone with one hand. One-handed mode helps your one-hand operation. The mode makes the screen smaller so you can reach the top with your thumb. You can adjust the size by swiping the corner of the screen. You can also move the screen to the left or the right for a left-handed or right-handed. There are two methods to enter the one-handed mode, Gesture and Button. Gesture means that you need to swipe up diagonally from the bottom left or right. Button means that triple-tap the home button activates the mode. To choose the method, go to Settings > Advanced features > One-handed mode (you can toggle the feature here), and select Gesture or Button. It’s worth noting that the mode continues inside any apps, and you can also enter the mode in any apps. To exit the mode, just tap outside the reduced display area or triple-tap the home button if you choose the Button method. Or, rotating the screen to the landscape mode also exits the one-handed mode.