It doesn't do a great job on Linux Mint 19 with support for GTK3. Hell this version is NOT RECOMMENDED by the Mate Dock team as they state on their own Gtihub! The version that comes with LM19 is v0.85 - the one on Github currently is v0.86. If you download and take a look at their own README.md it says the only version that supports GTK3 provided by Linux Mint is v0.80! SO WHAT'S THE POINT to make this version available for the newest Linux Mint? Mate-dock v0.85 does not display some icons, especially the ones you run under Wine (or Windows applications) - it just won't display them, you're forced into using Alt+Tab ALL THE TIME! Sometimes, even after opening up an app from the launcher makes the launcher icon to flash continuosly, it's annoying! And after you've successfully launched an app and then minimize it, mate-dock just won't unminimize it, rather it will just flash the icon repeatedly, again forcing you into using Alt+tab all the time. So again, WHAT'S THE POINT for using this applet?!
This is a cool app. However the version here is quite outdated and will not work at all because it is for GTK2 and the Mate desktop (and newer versions of this app) already evolved to GTK3. I would suggest following the instructions at the official github page to install it: https://github.com/robint99/mate-dock-applet
does NOTHING! even after re-boot.