[grantcox]

@davycro just said "it’s a tough skill to learn without a solid background in anatomy". If you have your home ultrasound and cannot accurately locate / track your baby, you may identify the wrong thing, and worry "it's not moving!"

Our first child came very late, and in those last weeks we downloaded a "baby heart monitor" on our iphone - it simply used the microphone with some isolation / amplification. We pressed the microphone end of the phone into the abdomen wall, and when it works we heard an amplified heartbeat out the speakers - very reassuring. But when it didn't work - when we couldn't find the heartbeat - we worried. Is it a false negative? Or should we rush to the hospital?

[davycro]

Or even worse you put the microphone on the epigastric vessels and hear moms heartbeat instead of the babies.

[michaelmior]

Why is this even worse? I assume you're suggesting it would potentially give a false sense that everything is ok when it isn't. But since such apps aren't intended as diagnostic tools, is it really a problem?