The UI couldn't be worse.

I see I've made custom slots, but there is nowhere to access them, not even a notification.

If you go to their website for help. you'd be glad to find the support section with a "How To's" subsection. Unfortunately it is simply the "Settings" subsection with a different title.

There's many other free crosshair overlay products far superior than this. There's also a few for only $5 that knock it out of the park.

Verdict: This is a simple money grab to try and get you to pay for overpriced pre-made crosshairs that are dog.