National Geographic Bird Guide to N. America.

This is a very easy app to use. The search feature is simple to follow and the illustrations are very clear. I wish that the birds of Mexico and Central America were included or have their own app.
All species that I have had to look up, I have managed to find, so to me it seems that most species have been inluded.

Mexberry about National Geographic Birds: Field Guide to North America, v3.3