Requires Android: 1.5 and up
Overview: 3G Watchdog Pro.
Guarding you against costly internet overages.
Pro version of 3G Watchdog mobile data counter / monitoring app, featuring:

•  Advanced data usage prediction
•  Billing rules (counts in blocks, ignores uploads, exclude apps)
•  Usage history with graph & CSV export
•  Usage by application (Android 2.2+, unavailable on Dell Streak)
•  5 widget styles
•  Backup/restore
•  Redesigned UI
•  Account/SIM with auto switch (requires a phone with a SIM)
•  Import settings & data from 3GW free (don’t uninstall 3GW free before importing!)
•  … and more!

Translated in Danish, Dutch, English, French, German, Greek, Italian, Lituanian, Polish, Portuguese (Brazil), Portuguese (Portugal), Russian, Slovak, Spanish, more on the way.
KNOWN PROBLEMS:

•  Doesn’t count properly global usage on Samsung Galaxy Tab 10.1 and 8.9 – this problem affects other data counting applications as well and is caused by a bug on the tablet itself. You may try to check the “Calculate global usage from usage by app” advanced option as a possible workaround (feedback welcome).
•  Doesn’t count properly global mobile usage on Samsung Galaxy R / Z (i9103) and possibly Galaxy Y. Problems were also reported with the Captivate Glide. Same workaround as for the Galaxy Tab (see above).
•  Early versions of 3GW Pro reported as not working on ZTE Blade/Orange San Francisco (black screen).

OTHER PROBLEMS:

•  If you run into problems and wish to help to solve the problem while giving the community a chance to get a better 3GW Pro, please send a mail to contact-pro@3gwatchdog.fr with details.

3GW Pro can’t possibly work perfectly on all possible phone models (more than 700 target devices) with all Android stock or custom versions + all manufacturers’ custom layers (such as HTC Sense) + all carriers’ custom layers + all combinations of installed applications, so please be understanding and collaborative rather than just angry if everything is not immediately perfect. Thank you.
-> See the FAQ at http://3gwatchdog.fr/faqs
V1.10.1 update:

• Bug Fixes (ZTE Blade crash…).
• Removed notifications in status bar when using the data mobile switch widget or the 3GW menu “Enable/disable mobile network” functions.

Screenshots