the author of this app says:
Windows Mobile software that helps prevent overages of minutes and text messages. It's capable of importing/exporting phone contacts and recording incoming/outgoing SMS, MMS, and phone calls. Monitors phone usage and sends alarm reports when overage thresholds are reached.
ActiveSync 4.1 or later. Windows Mobile 5/6. Dot NET Compact Framework v2.0. Data plan/Internet connection with mobile provider.