This is an Overwolf app. Overwolf is a program for Windows that allows you to use apps in an overlay when you are gaming.
This one gives you a crosshair. It used to allow toggling for ADS, but unfortunately the methods available were too laggy to be worth it.
The recenter and pixel adjustment buttons only work in game since they are dependant on game window resolution. Hotkeys (hide/show and close) also only work in game. These can be configured in Overwolf settings.
To install: Download this folder from Google Drive. Download Overwolf. Open Overwolf. Go to the settings page. Under the support tab there should be a "Development options" button, click on it. In the new window that pops up, click Load unpacked extension. In the File browser, select the crosshair folder you are currently inside of.
The app should automatically be added to your Overwolf menu.