XDM software starting up on login but not present in Login items
We have to change the settings below in the XDM application (Tools -> Options-> Advanced settings -> View settings.)

I used homebrew to install XDM and this option is selected by default.



If you look at the source code you'll find that the automatic start is controlled by a LaunchAgent called org.sdg.xdman.plist stored in ~/Library/LaunchAgents. 

public static void addToStartup() {
  File dir = new File(System.getProperty("user.home"), "Library/LaunchAgents");
  dir.mkdirs();
  File f = new File(dir, "org.sdg.xdman.plist");
  FileOutputStream fs = null;
  ...