Sample Android Traffic Statistics App. More info: http://www.itcuties.com/android/how-to-get-running-process-list-and-traffic-statistics/
itcuties/Android-Traffic-Statistics
"Today we got little application which displays list of working applications on Android in a ListView. When a process name is clicked application displays information about amount of data that application used – traffic info. This is a tutorial material." Feel free to use it. Full description can be found at itcuties.com
Java