Designer Tools is described as 'is intended to help designers and developers with routine work. It contains a loupe tool that helps you copy the color of any pixel on the screen' and is an app in the Photos & Graphics category. There are five alternatives to Designer Tools for Windows, Mac, PortableApps.com and SaaS. The best alternative is PicPick. It's not free, so if you're looking for a free alternative, you could try Red Lines Tools. Other great apps like Designer Tools are PixelSake (Paid), xScope (Paid) and Ruler (Paid).
PicPick is an all-in-one software for software developers, graphic designers and home user. It has an intuitive interface and simple, elegant operation. After starting the software, you simply select one of the tool from the PicPick Tools trayicon menu when you want.
PixelSake is Windows App to measure distance any element image on screen. It's a tool to make Web Developer / Web Designer easier to measure things so they can save more times than just measure manually the screenshot with old way.
Ruler is a lightweight tool for Windows. It allows you to measure the size and distance between elements on the screen in pixels. Features Create, layout and adjust custom marker boxes that float on top of all other on-screen elements.