Im using this indicator for horisontal line http://www.plutofx.com/PlutoFxHLine/default.htm - One advantage with this is that you can choose to see the line in some time frames but not others.
indicator print for 1 bar less than expected. for example it prints for 5 bars on H4 instead 6.
See my post number 8 in this thread. It is how the drawing of the line connections you've mentioned in the post #4 are avoided.