The LoRa Meshtastic T-BEAM device are small battery powered devices that will mesh with other T-BEAM and send messages and other data from your phones, tablets and computers. They can use one of three different license-free bands, but you do need to check for compliance in your own country as, for example, the 915 MHz license-free band is not necessarily a license-free band in other countries.
The plain broadcast capability can be better replicated using license-free walkie-talkies, but the real niche here is that these devices will create a mesh network. This means that if you are in the outdoors somewhere and a party is slightly split up, the message will relay though intermediate stations it can reach. Yes Android has the Briar app that I think does this, but nothing exists on iOS devices for this, so using these devices, Android and iOS devices can all interconnect (not the iOS device requires a beta version of the software app).
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Wireless, Off-Grid, No-License Communication For $27.99 (LoRa Meshtastic)
by Ham Radio Crash Course on YouTube