I added a response to the thread "LineReader is linked to mouse", and I notice that after I added that response nothing shows up in the thread except the original posting.

So anyway....

That thread talks about the need for a line that is not tied to the mouse, so for example it is possible to have the line on the current row of text in one screen while working in another screen.  Since the line is not tied to the mouse cursor you can use the mouse anyway you want on the other screen.

The suggestion in that thread is to use a rectangle shape.
I have tried that, and do not like how it works. 
It is not possible to make a rectangle shape thin at all; the minimum is 30 pixels.  I want a thin line that I can put between rows of text on my secondary monitor, not a big thick rectangle that blocks at least one row of text.  I can make the rectangle as wide as I want, but it won't allow it to be less tall than 30 pixels.

I realize that I can right-click on a shape, choose 'Select Color', and change the alpha level to get transparency on the rectangle.  That is definitely better than a 30-pixel thick opaque shape, but is definitely still not the same as a thin line that you can put between rows of text.

We will provide the following: a lower limit of 5 pixels for a shape. This lower limit of 5 pixels should be a thin enough line because going lower than that would be hard to grab the shape quickly in order to drag it around.

To change the alpha level for a shape in Line Reader you would indeed need to click on the shape (to tell the application which is the current shape) then right click the shape, then select the color including the alpha level and then click on the Get Color button.

This feature has been released. You can now make the rectangle shape (or any of the other shapes) as small as 5 pixels (in width or in height). Make sure to download the application from the product page:
http://www.iconico.com/lineReader/
by pressing the Download button.

Please notice that you can also build your own shapes by clicking on the "Shapes Window" button in the "Shapes" tab. You can build and store (for later usage) as many custom shapes as you want.