I use two of those on a small 15 watt 12v solar panel / SLA Battery charger. One reads voltage and the other reads current. They work pretty well and are fairly accurate when compared to my calibrated Fluke DVM.
Those results are pretty typical of what I've seen of those meters. They work perfectly and are surprisingly accurate for the price. The one I have has outlasted all of my other meters!
Yeah, if you set it up for current and put it across the mains, it's going to fry.