How to Write an App Review from Your iPhone
Sometimes you love or hate an app so much that you want to tell the world about it. In that case, you can write a review of any app directly from your iPhone.
Tap the App Store icon to launch the App Store.
Navigate to the detail screen for the app.
Scroll down the page to the Reviews item and tap it.
From the Reviews screen, tap the New Document icon.
Tap the Write a Review button.
You may or may not have to type your iTunes store password at this point.
Tap one to five of the dots at the top of the Submit Review screen to rate the app.
In the Title field, type a title for your review.
In the Review field, type your review.
Tap the Send button in the upper-right corner of the screen.
After you submit your review, Apple reviews your submission. As long as it doesn’t violate the (unpublished) rules of conduct for app reviews, it will appear in a day or two in the App Store, in the Reviews section for the particular app.