Automatically turns off 3G data connection when device is connected to WiFi network to reduce battery usage.

Measures time spent on each app. See which apps to uninstall because you're not using them!
The most accurate app usage tracker! Accurate to less than a second on Android 1.6 and up.

Pro add-on for AppUsage. Install AppUsage first, then unlock extra features with this add-on. Currently opts you out of data collection; more Pro features coming soon!

As also found in the official Google Android Market:

This application is a call minutes, sms, mms and data usage meter to monitor your credit usage. Never exceed your quota again!

Supporters unlock: free times/contacts/groups; widget; usage log; greater configuration of plan inclusions + more. A free 5 day trial is offered.

Please report bugs!

Please visit http://creditusage.matthewwardrop.info for more information.

What's eating my network data? Time to get a data usage monitor!

Smart Data Watch is free app to monitor your network data usage and convert the usage as your currency also lets you to set quotas for daily,monthly usage