Just like Star Walk, Night Sky Pro uses augmented reality to identify what you can see and what's beyond the reach of your eyes.
The interface is clever, as it puts several options in the corner as icons and has a "time machine" tool at the top, which you can use to spin forward or backwards to see how the sky will or used to look. I also like the weather predictor, which tells you how favorable the conditions are for stargazing.
If you're unsure if this whole stargazing thing is worth a measley $2.49, you can check out Night Sky Lite (free) or The Night Sky ($0.99), which stagger the features depending on how much you pay.
It's worth it to go with Night Sky Pro, as it includes the time machine, deep space objects, and other perks not found in the free or cheaper edition. Also, as the new flagship to the family, I would expect to see more features and frequent updates to this edition.
Night Sky Pro ($2.49)