None of mine are 8 specific but I have had a not 1,2,3,4 and now the 8 and have made it a joy to work with easily.
Oh, Except for Button Remapper. Used to set up alternate actions for single, long and douple tap options on Bixby (Home, Screenshot and Kill Foreground App)
I Use Next Launcher as I paid for it and love it despite never using the 3d mode. Nova is likely to be just as good for most folks.
I have 3 home screens.
Prime home is my various folders: Fun, Tools, Work, Media, Tech ETC.
A verical widgetzoid strip with 3 stage brightness (25,40,100) and 3 stage timeout (30s,2m,5m) as well as torch and wifi hotspot though these are now available in the pull down.
Left of Prime is a full screen widget for Simple Calendar Widget, set to read 6 months.
Right of Prime is a Transparent Weather bar, A large Terratime Globe complemented by NASAs Phases of the Moon. Under that is the ISS detector so when the sky is clear I might catch a transition (though being in Scotland that is not very often)
I did find a very nice search tool and I still find it more useful than the native swipe down search in Touchwiz (Next launcher has custom swipe down action) and that's Conjour.
Yuo can search for volume and it diplays sliders for each of your volume settings (media, ring, noti etc) it will find apps or let you search the web in various ways. Previously selected results are diplayed in reverse date order.
Tech apps I always install are:
ES File Explorer
Fing
Tasker - locate my phone and turn torch on from Pebble watch(handy when the stair light goes and I have shopping in both hands), mute my phone when on office wifi and a few others.
Titaniums Backup
X-plore
Airdroid
Goggles (though being killed off and currently can't take photos, Booo!)
Sky Map
Media wise outside the norm it's:
MX player for those formats not otherwise supported.
Google Home for my mini and cast.
Plex for my home plex server of course.
I've also recently discovered the Rocket Book though that requires an external notebook and they're not cheap but are re-usable. Absolutly fantastic for meeting notes etc.
Game wise the only one I still can go back to is Plague Inc. I'm thinking of ditching Words 2 due to excessive advertising and no opt out.
I do also root my devices as Titanium Backup requires it, I prefer the circle battery indicator and stopping the silly popup when connecting bluetooth, blocking youtube ads etc. Xposed modules take care of the mods. There's also one that drops the mobile data antenna down to 2g while on wifi as that uses less power than the 4g.
Settings wise on the Note 8
I'm running in full WQHD mode just for when I muck about with the VR so I want to save Battery.
For this reason I installed the Maretial_Black theme. Though I've always used a darkish theme it was a bit jarring but I like it now. It works well with the Peaceful theme icons from Next Launcher.
It's also the reason for the 3 brightness settings above. With a black wallpaper, and for general usage 25% brightness is plenty, 40% for when tyou want to show your screen to others and 100% for sunny glare.
I've uninstalled Greenify for now to see how the built in power management works and so far it is pretty good.
Lastly, the Note 8 is one of the few but growing phones compatible with Googles Daydream VR environment. It's worth a look for kicks and giggles and can only get better with time. It's still a novelty but the official headset is comfy, the controller is mostly easy to use (aside from the long press to recenter has a short press of quit). There are some great discovery channel episodes in full 3d for example and Within is a 3d experience agregator.