i saw some mention that a "starmap hd pro" version was coming for $20 and would have more features than this $1 version. wasn't on the official site though.
for $1. this is worth picking up if you want something to look at the heavens with. it's less than a big mac. but i'm no expert, barely an amateur, starwalk seems to work fine for me. i can stand outside with it on my ipad/iphone, face a direction, and see on the screen exactly what i see in the sky. if i turn, the view rotates right along with me. i couldn't figure out how to do that with starmap.