Too early to tell
Im at 11 weeks now and I had this app since I was at 9 weeks, I was sure I heard the heartbeat but it turned out it was a feedback (some sound was entering in the mic from the speakers and it was looping to create something very rhythmic and constant). This feedback is an issue because its very confusing. I tried again today and I still have the same issue.
BabyScope - Prenatal Listener, v4.3.1