Voxer Pro Business turns your smartphone into a walkie-talkie. Smartphone walkie-talkies are not new, of course — Nextel, which got swallowed by Sprint, used to offer a unique push-to-talk, or PTT, walkie-talkie cellphone feature called “Direct Connect.” Nextel’s simulated half-duplexing service mimicked walkie-talkies but ran over spectrum similar to that used by cell networks. The all-voice service was popular with fleet and dispatch users but never took off across all user bases.
