DataMan 3 for the iPhone logs your 3G and Wi-Fi data transmissions. For 3G data you can set daily, weekly and monthly thresholds, and DataMan will provide an alert at various designated levels. This is a must-have app.
In addition to setting quotas to make sure you don’t overrun your AT&T billing limit, you can also call up a map to see where you were when the data was transmitted.
Normally, an iPhone app has access to three background APIs: music, location services and VOIP. I asked the developer about how he logs data in the background, and he said that he found a way that’s okay with Apple. (Obviously, as the app has been approved.) When the App is launched or comes out of multi-tasking suspension, it has access to the data it needs, and that’s all the developer, Johnny Ixe, is willing to divulge.
Alerts, by default, occur at 50, 70 90 and 100 percent of your monthly allocation. These can be adjusted.
Logging 3G data is not currently compatible with the 3G iPad, but will be when iOS 4.2 is released. The app can also monitor your Wi-Fi usage on an iPad, iPhone, or iPod touch, but because we don’t normally get charged by the byte, that isn’t so useful. The app is not universal, so it remains in the smaller screen format when used on an iPad.
I haven’t used the app long enough to rigorously compare to AT&T’s data. You can access your AT&T log of data for the month and even generate bar graphs of usage. Jeff Gamet explained how to do that back in June. However, I did compare my AT&T report to DataMan for October/November and the numbers were fairly close.
This app has many good purposes. You can compare your logged usage to AT&T’s. You can see where you were and the path you took when you were transmitting, and you can get real time alerts to make sure you don’t exceed your limit. If you think AT&T has over-charged you can do some research to find out usage you perhaps weren’t aware of. Alternatively, you have a sanity check on their billing.
DataMan 3.0 is multi-tasking aware, requires iOS 4.0 or later, and is priced at US$1.99. I wouldn’t dream of being without this app.