Ironically, Ars is a site that is really atrocious on mobile Safari, ad wise. I visit there regularly, and often I get full page ads that block the view.
I recommend the Reader mode in safari. It's the closest I've come to "ad block" on an iPhone. It can take an article on an absolutely atrocious website, with hovering top and bottom bars, hovering ads, etc., and transform it into pure heaven: beautiful text, on a clean background, with relevant images.
