Thanks for your question. Yes – the majority of people on Cape York have smartphones that can run and operate an app, including having access to major app stores for Apple and Android.
Particularly Android smartphones are becoming more affordable, especially with mobile plan options. However it’s good that you are checking whether people would have access to these devices first. Rangers, who would be more likely to be using this solution, especially have good quality smartphones and iPads.
Hope that helps and best of luck with your project,