The Samsung Galaxy S8 represented a departure from previous iterations in that it uses software-based navigation buttons versus the capacitive keys/physical home button combination of yore. This change led to the creation of a modification that can make the Galaxy S8’s navigation icons look like the Google Pixel‘s.
To make the change, download any of the .apk files listed in the XDA Developers thread below. Since these are files not found through the Play Store, you will need to allow installation from unknown sources within the Settings menu. After that is done, install the files and reboot your Galaxy S8 or Galaxy S8 Plus. Once you power up your phone, you should see different navigation keys, along with support for rotation and transparency.
There are a few things to keep in mind, the biggest being that any of the .apk files only acts as an overlay – it does not outright replace the default navigation buttons. You will notice that detail when you hit the home button, for example, since it goes back to the default home button when pressed.
Also, if you use the always-on display, the default home button will show up, but that is not a bad thing – the button slightly moves from side to side to prevent screen burn-in, an issue with AMOLED panels.
Finally, you cannot disable the overlaid navigation buttons from within an app. If you wish to go back to the regular navigation keys, uninstall the download .apk file from the application manager and reboot the phone.
If the caveats do not dissuade you, the discussion thread has plenty of .apk files to choose from, one of them being an overlay that makes the Galaxy S8’s buttons look like the Pixel’s. Best of all, other .apk files include stock Android navigation bars, navigation bars with a menu button, and no navigation bar at all.