Grid Ruler is a free Chrome add-on developed by tgohn. It falls under the category of Browsers and specifically, Add-ons & Tools. This program allows you to easily create and measure grids, similar to Photoshop style.

With Grid Ruler, you can create both vertical and horizontal grids by simply dragging from the main vertical or horizontal ruler. This feature makes it convenient for designers and developers who need precise grids for their projects. Additionally, the program includes a ruler that allows you to measure the distance between your created grids.

One of the key features of Grid Ruler is the ruler mode, which can be accessed by clicking on the intersection of the vertical and horizontal rulers. In ruler mode, you can hold the Shift key to get a straight line, ensuring accuracy in your measurements.

Overall, Grid Ruler is a useful tool for anyone who needs to create and measure grids quickly and easily. Its intuitive interface and Photoshop-style functionality make it a valuable addition for designers and developers alike.