One of the most frustrating health issues a parent faces is ear infections. Sometimes the child is too small to tell you what is wrong. Sometimes you just don't want to drag a sick child off to the doctor to discover there is nothing that can be done to make them feel better.
So this looks very promising:
"In its current form, the app sends short, sound pulses through a funnel and into the ear canal. It then measures the echo of that sound, and an algorithm uses the reading to predict if there's fluid behind the eardrum, one of the common symptoms of infection."
The app is still being developed and will need FDA approval before it can be marketed but it will hopefully be useful and a great comfort to parents.