Start iTerm if not started, close first window that pops up

com.bartnett.itermonlogin.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>Label</key>
	<string>com.bartnett.itermonlogin</string>
	<key>RunAtLoad</key>
	<true/>
	<key>ProgramArguments</key>
	<array>
		<string>osascript</string>
		<string>{/path_to_your_script_folder}/launch_iterm_nowindow.applescript</string>
	</array>
</dict>
</plist>

launch_iterm_nowindow.applescript

# Check if iTerm is running, if not then
#   1. Launch it
#   2. Close the first window that opens
#   3. Reactivate previous application

on appIsRunning(appName)
	tell application "System Events" to (name of processes) contains appName
end appIsRunning

if not appIsRunning("iTerm") then
	set current_app to (path to frontmost application as Unicode text)
	if the (count of windows) is not 0 then
		set current_window to name of front window
	end if
	tell application "iTerm"
		activate
		close current terminal
	end tell
	
	tell application current_app
		activate
		activate current_window
	end tell
end if