FreedomPop today announced it has jumped onto Sprint’s CDMA airwaves and expanded its potential coverage by more than 220,000 Americans. The freemium mobile broadband provider, which guarantees customers 500 MB free per month, had previously only operated on Clearwire’s WiMax service.

The Overdrive Pro, a 4G/3G hotspot, is now available for order on FreedomPop’s website for $39.99. It’s currently the only device FreedomPop offers that can switch between networks, but the company is offering to swap for free with any customers who already bought the company’s Photon hotspot.

FreedomPop’s plans still start at $0, but that only provides 500 MB free of WiMax—which limits usage to only the markets Clearwire covers. Plans providing access to both Sprint’s CDMA and Clearwire’s WiMax networks start at $3.99 per month for 500 MB and jump to $19.99 per month for 2 GB. As before, all plans still offer the chance to earn more data on FreedomPop’s platform by recruiting friends, playing mobile games and engaging with promotions.

“Since our launch, we’ve been turning down about half the people that come to our site to sign up because we don’t have coverage in their area,” said CEO Stephen Stokols.

Stokols explained that FreedomPop’s expansion will serve as a stopgap and to raise the company’s profile in advance of its anticipated launch on Sprint’s LTE network later this year.

Since its beta launch in October 2012, FreedomPop has expanded its device portfolio to include iPhone/iPod Touch sleeves enabling access to WiMax and wireless routers to offer home broadband service.