Freedompop has said yes to byod. However, other details are still not concrete.
Launch date is just stated as approximately the end of summer. Phone must be an Android as there is an app that must be loaded to the phone. No other smartphone operating systems, and no feature phones seem possible.
Also unclear is what speeds the voip requires. It cannot be 4G LTE because Freedompop has specifically stated that they did not want to wait for LTE to be available nationwide on Sprint. It makes more sense for the voip to use Wimax as Freedompop says Wimax data costs much less than Sprint 3g data. Using Wimax though greatly reduces coverage area. Plus Sprint is moving away from Wimax, so there are only a few devices that support it. Using 3g would give the largest coverage, but that is not the least expensive method for Freedompop, and the speed is probably not fast & reliable enough for voip.
For what it is worth, the phones Freedompop have mentioned for the free service are Wimax devices. To further confuse things, their CEO said it is possible to bring in a Galaxy 4 which is a LTE device.
One possibility is that the free service is wimax, while 3g or LTE is an additional charge.
It is also not known how much (if anything) Freedompop will charge for byod.