I've been wanting to try it but I just feel like my phone can't even give me an accurate weather report so a doppler you can buy on iTunes may not be the most accurate. If you try it let us know how it works!
I bought MyBabyBeat for around $4.99 for iPhone 6 and honestly, it hasn't really worked for me. Maybe I am just not patient enough or haven't tried enough to find my baby's heartbeat. I'm sure there are free apps you can try first. This one got good reviews so I thought it would work better. I am 22 weeks today and did not find the heartbeat but I can feel all the movements! So she's in there hanging out. Good luck!
They only work when you can hear the HB using a stethoscope. Your phone doesn't have ultrasound like a doppler so won't be able to pick up anything unless it's audible without the use of ultrasound. Some of the apps are a big scam, when you put your phone onto anything, you'll hear a HB, bananas, furniture, anything.
All these apps do is allow your microphone broadcast the heartbeat audibly. So if the hb is loud enough to be picked up by your phone's microphone, you'll hear it.
I have the BabyScope app which after a couple of days trying to find the heartbeat, it sounded exactly as if I was hearing it. I became so very excited and sent sound clips to family members, etc. A week or so later I tried it on my own heart and it sounded exactly the same as it did on my abdomen...much faster than my own heart rate was. Then pretty much anything on my body I put it on had that same fast heartbeat sound. Not sure if it was a recording or what but definitely seemed fishy to me. I at least wouldn't go with the BabyScope app.
I have the MyBabyBeats and was able to pick up my baby girls heartbeat very clearly at 23w5d today! I was able to capture it on a 37sec recording and whats great is throughout the 37sec, you hear these loud thumps that are her kicking (or whatever she is doing in there) at my phone that was against my belly.
ETA: Babygirl was very close to the surface of my skin and my placenta is posterior fundal so, if you have an anterior placenta, or depending on placenta location, you could be picking up the sound of your placenta pumping (more of a swoosh sound) or it could be the reason some are not able to pick up HB at all.
I use the MyBabyBeat app as well, and I've tested it on my arm and other parts of my body and I get no sound like when I heard the baby's heartbeat. It sounds exactly like when my doctor uses the handheld doppler everytime I got to the doctor just a little quieter. This is just my personal experience. I'm 23 weeks.
Re: Doppler App??