title: How to use radio waves for an app?
body: <p>Am developing an app in which I want to use radio waves as an s.o.s tool. From what I know a phone can use radio waves without a sim or other network connection I.e. Emergency calls. How ever I want to use that tech for sending something other than calls like messages or videos and audio recordings. Is that possible, if so how and what is the code for that?</p>