Assists in setting up an optical sight and gives estimates for distances in between known settings. Very handy for first time optical sight users.Basic Usage:To use the app, when you first open it, you click the (+) symbol to add a sight. Fill in as many distance/pin settings as you can, and then click the tick in the top right corner. Once you save, you will have a list of sights. Click on a sight and it will show a table of distances from 10-100m. You can also input a custom distance (from a range finger) and it will calculate the ideal pin position to shoot that distance. You can edit the sight by adding more pin settings by clicking the 3 dot menu at the top right. The more pin settings you add the more accurate it will be.