Well-designed but no updates
5 stars for the design, clear presentation of material (especially if you like the printed NGS guide like I do), and vocalizations (the sonograms are a nice touch) but 3 stars for the lack of at least annual updates and app upkeep. Like all of the natural sciences, ornithology and taxonomy are constantly changing and it puzzles me why this app doesnt bother to stay current with currently accepted AOU and ABA taxonomy.
Empid about
National Geographic Birds: Field Guide to North America, v3.5