Ann: ResApp Announces SleepCheck, a Sleep Apnoea Screening App, page-36

Polysomnography is the gold standard. ResApp can likely provide a reasonable indication of breathing rate and count how often patient stops breathing. This is very useful but it's an indirect measure, and there's a lot more to OSA diagnosis than just that.

Deloitte Access Economics estimates that OSA costs the Australian economy $21.2 billion annually.

This is just in Australia... think about it for a second!