Grid Lines Ruler is a free Chrome extension developed by v & g. It falls under the Browsers category, specifically the Add-ons & Tools subcategory. This extension allows developers to create grids on web pages, providing them with visual hints to aid in the development of web app layouts.

Setting up Grid Lines Ruler is a breeze. Simply download and add the extension to your Google Chrome browser. Once installed, click on the extension to activate its functionality. You can then drag from both the vertical and horizontal rulers to create grids on the page. To enter ruler mode, click on the intersection of the vertical and horizontal grids. For straight lines, hold down the "SHIFT" button.

Grid Lines Ruler offers several useful features. Firstly, it is completely free and easy to set up. It enables the creation of both vertical and horizontal grids, allowing for precise layout development. Additionally, it provides a ruler to measure the distance between grids, ensuring accurate placement.

With Grid Lines Ruler, developers can easily create and manage overlays on web pages, providing them with the visual hints they need to develop web app layouts effectively.