I get a little bewildered at how many rely on a normal mobile phone to get them out of the proverbial ? Maybe and only maybe in Vic or more densely populated areas perhaps but again maybe only. FNQ, NT,WA and SA remote areas forget it. You can have network coverage walk merely 100 metres and lose it. Try crawling 100 metres just for the hell of it and see how you go? Then try it with a broken hip in 40+ temps?
So not much fun if you send out your SOS whatever and who you think has got it hasn't? Meanwhile the time clock is ticking on your snake bite, or even time from injury to treatment being received in many cases can be a deciding factor. This is just my humble opinion as after all only you can decide what you choose. I could add quite a few stations have closed due to not wanting the responsibility of having to rescue people. So topic could be headed "How do station owners view prospectors" also perhaps.
Stay safe
Here is a review from an app user which sort of says it all
Dangerous app. It thinks I am at my old address, some 50km from where I actually am.