Allows you to keep a track of bandwidth usage by application
Allows you to you manage applications by data usage
Allows you to find out which application has the most data usage
Requires Android version 2.2 and above
Below the "App Name" tab you would be able to see a list of the applications currently running on your phone. You would be able to see data usage for each application in the "Received" and "Sent" columns.
Below the "Graph" tab you would be able to see a graph which displays the correlation between the applications running on your phone and their respective data usage (Download and Upload).
Below the "Settings" tab you would be able to setup an email notification which would include a daily usage report for the applications on your phone and their respective data usage.