App adds itself to Login Items each time it starts

Contact Unified Intents AB

Your best option is to contact the developers of Unifed Remote directly. This way they will know it is a problem and may be able to offer an immediate solution.

AppleScript Removal of a Login Item

Otherwise, you might want to investigate scripting the removal or quitting of the Login Item. The Mac Stuff web site has a good overview at Adding and deleting login items using AppleScript:

tell application "System Events"
    --Find out what login items we have
    get the name of every login item
    --see if the item we want exists.  If so then delete it
    if login item "home" exists then
        delete login item "home"
    else
        display dialog "That login item doesn't exist"
    end if
end tell