The other is less realistic but focuses on weapon hold, breathing and sight picture (I can't remember the name of it). You hold a mock up M16 again (but a less realistic one) and you shoot at a monitor. Afterwards, the program will show you how your point of aim changed as you aquired the target, aimed and squeezed the trigger.
Not for pubic consumption though- I'd reckon there aren't that many of those systems out there and they're big and bulky. Just throwing it out there for trivial purposes.
It's been around for 15 years. Spend an hour a day for a week on that device, and you can go from a somewhat shaky shooter to a damn good shooter. (Personal testimonial here.)