If you’re trying to learn the celestial navigation stars, this is the app for you!Celestial navigation is a niche topic, and learning the navigational stars is a niche within a niche. That being said, the app does exactly what it needs to. It lets you learn the stars for your or any location, for any time of year. You can test your knowledge of either the stars or their constellations. The only things I had to go outside the app for were the pronunciations (stars and constellations), their meanings and the artwork for the constellations. I find it MUCH easier to learn star/constellation names if I know the Arabic/Latin/Greek meanings, and what they look like.