Pretty Good
This worked better than I thought it would. Im only 6w4d, but I could hear what was definitely my babys heartbeat (sounded like the same pace as the ultrasound I had two days ago, just not as clear). The mic is really sensitive, so the sound gets kind of polluted, but if you dont move the phone too much, you can hear the beat.
Ko318 about
MyBabysBeat - Fetal heartbeat