HaloGP. You can't miss it, it's right at the top of their website (also where you can find the apple version if you're so inclined. It doesn't score well on either platform).
Apparently worth a bit less than $14. It's fringe stuff, even for most Seventh Day Adventists, and extra conspiratorial in what it proclaims.
(Bonus: The reviews on the above link have back-and-forths between conspiracy theorists.)
Walk up to their premises on a Telstra phone. I know staff who have Telstra network phones that work perfectly fine. That area is geographically between mobile towers - you can check this yourself with apps like this OpenSignal. It has a compass pointing you to the nearest tower.