The low-cost Sprint MVNO FreedomPop just launched its freemium phone service last month, but now it's expanding phone selection by letting users bring their own handsets. However, that doesn't mean you can take just any Sprint device over the FreedomPop and kiss your bill goodbye – there are some restrictions.

FreedomPop has to work within the confines of Sprint's system, and that means it can't activate most handsets right now. However, the carrier does have authorization to activate a number of older devices including the HTC Evo 3D, HTC Evo 4G, Samsung Galaxy S III, Samsung Epic 4G, Samsung Epic 4G Touch, and the LG Optimus S. The MVNO is also working to allow unlocked phones like the Nexus 5 to work with its service and should have this sorted out soon. The company is also selling a batch of old Evo 4G handsets for $99 off-contract.

FreedomPop offers a basic tier of VoIP/IP service with 200 voice minutes, 500 texts, and 500MB of 3G/4G data for free. You can pay a few dollars per month to get unlimited calls, texts, or more data. Users simply download a companion app that handles all the VoIP features, but FreedomPop only has access to Sprint's WiMAX 4G network, which is obviously not in great shape.

[PR NewsWire, FreedomPop]