"Centercut"Chairgun is just fine, no worries. Strelok and Strelok Pro are cell phone apps, so if you tried to download it on your computer I'm not sure what you were trying to do? I was tickled pink with Chairgun at first also. The cell phone pic below is what you see when you look at your phone after your Strelok is set up for your gun, scope and ammo. You can also easily change the magnification slider and it'll change the holdover points automatically. In this case I had 107 yards, flat ground, and a slight 2mph breeze right to left, so it shows the yellow dot where I need to aim. You don't have to have the squirrel in there, it can be a rabbit, rat, coyote, red dot, or a target, among many other choices. Anyway, its all good...