I have use NetMonitor on over a dozen devices and never had any issues with it damaging or ruining any of my devices. I don't think it's even crashed before.
The accuracy is the only issue. NetMonitor is dead to rights accurate in the Albuquerque market. But when I go to Texas, most sites are shown with the offset sector method and not directly on the site.
Robert via Nexus 7 with Tapatalk HD