App Shopper

Price: Free!
Grade Recommendation: All
Subject: All
Specific Skill: Locating new apps
Levels: n/a
Players: n/a
For iPad, iPod, or Both: Both

Rather than an app for student use, App Shopper is a resource teachers (and parents) can use to see what apps in Apple's App Store have been recently updated, added, and/or experienced a price change (usually a decrease). You can search through the entire list or filter by price (free or paid), type (updates, newly added, or price change), and/or category (Education, Productivity, Books, etc.).

I check this app daily. Updates available for your apps will automatically show up in the App Store app. New apps generally are not of interest to me because they have not yet been reviewed. However, being able to monitor price changes is beneficial because it allows you to snatch up apps that temporarily (usually for a day) have a price decrease.