I'd be hard-press to call any of the features of the S-Pen "everyday" features (and that's even if you are a daily note-taker), but other than the accelerometer for remote scrolling on the browser or opening the camera/taking pictures remotely, not sure there are any features you'll find that aren't on the Note 8 already.
If that's your thing, AR Doodle is cool, but again, hardly something I'd see myself using every day. If you use DeX on a daily basis and you fancy a more appropriate mouse, you can install S-Mouse and use your pen as a magic wand to control the cursor on screen (just bear in mind that movement is a bit jumpy at times, and it only works as long as you aren't holding your pen vertically as the accelerometer is disabled in the pen when it's in a vertical position).