1px: Simple ruler is a free Chrome extension developed by Nevzilya. It falls under the category of Browsers and is classified as an Add-ons & Tools subcategory. This extension serves as a simple ruler for measuring the size of blocks on a page.

With 1px: Simple ruler, you can easily measure the width and height of any element on a webpage. The extension provides a convenient way to accurately determine the dimensions of various elements, helping web developers and designers in their work. To exit the ruler, you can simply press the 'ESC' button or the extension button.

While the current functionality is limited to measuring elements, there may be potential for additional useful features to be added in the future. For now, 1px: Simple ruler offers a straightforward solution for measuring the size of blocks on a page.