Used It Every Day - Til now

12/2014: I used to depend upon the cellular data usage monitor in this app. After I got used to where and how to use the Adjustment feature, it was very useful. But two situations have rendered it useless: 1) adding a line with shared data plan; and 2) rollover data. The app doesnt see the other phones usage, and theres no way Ive found to enter or retain rollover data allowance.

Blue Buckeye about Data Monitor - Manage Data Usage in Real Time