That annoyed BEEP BEEP from NEXTEL phones in the 90s (sound in comments) : r/nostalgia
Cómo hacer que tu teléfono Android o tu iPhone funcionen como un radio Nextel | Zello walkie-talkie | Play Store | App Store | radio | Tecnología | La República
Motorola I530 Amarillo Rugged Walkie Talkie Nextel o Boost Funda para teléfono Celular : Amazon.com.mx: Electrónicos
Walkie-talkie voice chat is coming - back - Komando.com
Nextel i880 - Review 2007 - PCMag UK
Nextel makes leap into 21st century
It's no accident that Apple chose a yellow icon for its walkie-talkie feature. I dug out my old (2002ish) Nextel with PTT (push to talk). It was all the rage back then... :
Direct PTT i655D Two Way Global Network, Analog & DMR All In One Global PTT Radio | Eventtone