Freedompop has gotten better since they started but you still should exercise due diligence to avoid the situations that make people feel robbed. Their zip-code locator told me I was in an eligible area and they also referred me to the Sprint map to double check which said I was in a Sprint roaming area. The Overdrive Pro I was ordering was, at the time, advertised as available with "3G roaming" so I ordered it with the intention of switching to the 3.99/mo "3G roaming" plan.
About three weeks later I noticed they were no longer advertising it as "roaming" so I opened a support ticket to double check. It turns out the advertised "roaming" was only within the Sprint network and I would not get any service from partner towers, at which point I asked them to cancel my order. At this time I do not believe they use the word "roaming" at all and when I run my zip code they no longer say I am eligible.
I personally do not believe they are a real scam, but I do believe they exercise sales practices that are poorly thought out and can be misleading. If I were in a truly covered area they would still interest me, but tread with caution and study your account settings carefully to avoid any surprises.
I thought my phone was pretty smart but I have been unable to teach it to swim.