Like in the title, I've used ShadowKiller (very old but worked until 10.11) but it doesn't work in 10.11 and 10.12 as well (tried disabling SIP).
I've tried using the command line trick, toggle-osx-shadows from github and couple of others, it seems that something changed in 10.11
Does anybody have a solution?
Best Answer
edit 01-11-2019: Works on Mojave.
There is a solution - plugin called winBuddy which is available through MacForge (previously known as mySIMBL).
It allows you to turn off window shadow and/or window borders for every app.
I've just tested it and it seems to work properly, there are some minor glitches here and there but nothing major.
Minor glitches include: