Laser Level Grid is an augmented reality (AR) application that makes it easy to hang pictures perfectly. By using your phone in one hand and a pencil in the other, you can eliminate the need to purchase a traditional bubble level and even measuring tools. The grid makes it easy to match the relative spacing between pictures and to center pictures in the space available. The angle finder feature makes it easy to instantly measure angles.

If the lines look a little off (not perfectly level) when you first open it, simply hit the calibrate button and follow the instructions.

Also note, the fish-eye cameras on phones bend the image at the edges and then software straightens everything out, but it isn't usually exact. If you are using the grid feature, use the middle lines for angles and the lines closest to the edges only for checking relative spacing.