does exactly what it says on the tin, and does it well. i, too, like that one reviewer below, have adhd, and it really helps. i agree that adding the ability to choose units/blocks of TEXT* i can't believe i wrote code for some reason, would be GGGGREAT :D but nevertheless, solid!
edit. i want to add that would be nice to have a toggle to choose to always show videos on a page in maximum brightness (i.e. without the dimming) when using white stripe mode
edit 2. although you can just disable the addon on pages with videos... yeah you can ignore that last bit lolz

5 stars as it does exactly what it says its does.

Some recommendations to integrate for better UX:

1. The ability to choose how many lines are highlighted simultaneously (units)

2. The ability to change the amount of lines the highlighted section is moving when pressing arrow keys to scroll through pages (eg 1 press of arrow key EXPLICITLY moves the highlighted section 1 line [or unit if you integrate the previous recommendation] down)

essentially create a variable to represent the number of highlighted lines, ill call it "unit" and allow the arrow keys to move the highlighted section by the "unit" amount

I have ADHD and this beauty really helps me with reading and understanding text, also it would be amazing if there was an option for highlighting 2-3 lines of code.

This add-on is a game-changer for me when it comes to studying or reading articles. My ADD makes it very hard to focus sometimes and when I see a big block of text, my brain shuts down. Now I can read line by line without losing focus. I am astonished that this extension is not more popular because it is fantastic. Thank you so much to the creator of this wonderful add-on.

Awesome. Very nifty useful tool. Thank you for beeing a good human. :-)

my favourite extension. It's simple, efficient, perfect.

This is a great addon and makes reading long chunks of text so much easier! I wish there was an option to pick any colour instead of the default 5.

This is the best virtual reading ruler I've found. Thank you. It helps me with Visual Snow Syndrome.

I wish I could use it to highlight whole paragraphs though, not just single lines. Haven't been able to find an app that does that. That would be amazing.

It took me a while to realize that the ruler icon appeared in the search bar and not the toolbar. Other than that, it does everything it says on the tin. I wish I had discovered this tool much earlier!

Works super well on anything but google docs, I really appreciate the new hotkey for on/off.

I can see this extension being pretty useful, but I think it would be better if the ruler was turned off by default. I only need it for certain things and having it on every page gets annoying pretty quickly. Edit: The added toggle feature makes it much more useful. Definitely a useful extension to have.

Amazingly useful add-on. Big thanks to the programmer! I read a lot of books online and have tried the Ruler (line highlighter) at Project Gutenberg, Fadedpage, and Scribd.com. Works perfectly. It certainly helps keep me focused and my eyes more relaxed. I might add that all the options, including turning the Ruler ON or OFF, are available in about two mouse clicks. (Look for the Ruler icon just to the right of the address/URL bar. Couldn't be more convenient.)

I have ADHD and this extension is awesome for reading texts without losing focus. Previously I would manually highlight every line as I was reading it. Congrats

This is the first time I'm rating any extension out of the dozens I use. It does exactly what it says. One thing which could be improved is a shortcut to enable/disable the extension. Additionally a global disable and then enable for each ones where required is an absolute essential.

It is a useful add-on.

So pleased to find this add-on as I've been looking for something just like this to help me with reading content in a second language that uses a different script. It's easy to get overwhelmed with all the text on the page, so having something that helps me focus just on the part I'm reading is really useful.
The one possible improvement would be the ability to set everything else on the page (everything not highlighted) to fade a bit, at the same time, to the background colour of the page. Initially I was looking for something that would give me almost a keyhole view on just the text under the mouse, so that's where that idea came from.
Also, it would be nice to be able to choose for the add-on to be disabled by default on new domains so that using it is "opt-in" rather than "opt-out". Right now I'm having to check the box to disable it on most of the pages I visit frequently (but on which I don't read long-form content). I'll get there in the end, but right now it feels like work and could discourage new users.
But overall am really pleased to have found this and very grateful to the developer.

It's criminal how less than 100 people use this add-on >:+( It's such a godsend, and knows exactly what it needs to be--no more, no less! The ONLY suggestions I have are to add options for "locking" a highlight in place and maybe a shortcut to toggle the extension on 'n off... But that's if I'm being nitpicky, this add-on is a gem, thanks a whole whole bunch! :+}