How to Use Your iPhone to Find Apps
Check out the detail screen from your iPhone.
To find out more about any app on any page, tap the app. You see a detail screen like the one shown. Remember that the app description on this screen was written by the developer and may be somewhat biased.
Tap the Reviews button (between Details and Related in the figure) to see the star ratings and reviews for that app. At the bottom of that page is another button: More Reviews. Tap it to see (what else?) more reviews.