I've tried FreedomPop in the past, and people were ranting and raving just as much as they are now, and it couldn't have been more of a scam.
I got a wireless Hotspot through an online promotion, and not only did the wireless Hotspot fail to work since day one, but to change or cancel your subscription plan, you actually have to call in and talk to a representative, which for me, included sitting for over 4 hours on hold. For what was supposed to be a $40 hotspot and free wireless broadband, I ended up sinking another $30-something dollars under false-pretenses.
ie. Be wary of this company and read the fine-print.