It's not horsepoo, but it's badly reported. It'll allow you to get 8x the power that is usually WASTED in a battery when you throw them away as dead, I.e. that last 5%... Great for low low power applications like clocks or smoke alarms, useless for higher power applications.
It's what's known as a Joule Thief - just in a neat new casing.
It definitely doesn't give you 8x power output!