On Screen Pixel Ruler / Reading Guide for Windows
The reading guide helps you read through text on your screen much like a ruler edge helps you read through lines of text on a printed page. This makes A Ruler for Windows an ideal tool for working with long e-mails, wide spreadsheets and fine print documents on your screen.
The program switches between ruler and reading guide modes with a mouse click or key press.
By default, both the ruler and reading guide come with four 'skins' to choose from: wood grain, stainless steel, plastic see thru and yellow construction. However, you can create your own skins and share them with your friends!
More information: https://www.arulerforwindows.com/