FinderPop still has a fiercely loyal following, of which I am one. I love it and frankly find myself going to extreme lengths to keep using it, even under Mojave 10.14.2 (18C54). If you're one of those people struggling without it and want it back, here's some instructions that were posted on Turly's forum ages ago for High Sierra that still work with Mojave with one additional step that I've found needing to be taken with Mojave that I'll add at the bottom. It even looks really good in Dark Mode!
1) Install the latest FinderPop version. (I use 2.5.9 beta from 22 Nov 2015. From here -
http://www.finderpop.com/FP259-BETA.zip - still working as of the date of this posting, but if not, ping me on the forum and I'll see if I can get you a copy from Turly.)
1b) execute (using the Terminal app): defaults write com.finderpop.finderpop ignoreSysVersionCheck -bool true
2) Disable SIP (reboot in discovery mode pressing cmd-r while restarting, in Terminal type command "csrutil disable", restart normal)
3) Open /Library/ScriptingAdditions folder
4) Move the FinderPopOsax.osax file in there to the /System/Library/ScriptingAdditions directory (creating the ScriptingAdditions directory first if it doesn't exist). Don't leave the file where it was, move it, don't just copy it. You will probably be prompted for an administrator password.
5) Open Terminal, and type command: sudo chown -R root:wheel /System/Library/ScriptingAdditions/FinderPopOsax.osax
6) You'll need to enter your admin password when prompted in the Terminal window
7) Enable SIP (reboot in discovery mode again, in Terminal type command "csrutil enable", restart normal)
8) Navigate to /Library/PreferencePanes/FinderPop.prefPane/Contents/Resources/finderpop-daemon.app
9) Drag that file into your account's startup items list, and away you go!
Hope this helps and best of luck!
MRJJ
