Ive nearly always found what Im looking for using this app. Im probably not taxing it all that much, just looking for the regular birds I see in my neighborhood, but it has never failed to ID a bird that Ive actually seen.
Where its not as useful is with bird song. Ive tried using it to ID a bird that Ive only heard, not seen, and that didnt work. If there were a way to narrow down types of songs and then give you samples to listen to so you could ID the one you heard, that would make this app absolutely bullet-proof.
Kathode72 about Merlin Bird ID by Cornell Lab, v1.0.4