The app works with your actual usage on your iOS device, not with the usage from the phone service. It keeps track and updates your usage every ten minutes. When I opened the app for the first time, it started not with how much I have already used this month, but at zero, and assumed my monthly bill started on the first of the month. For reviewing purposes for this article, I reset the billing date to the day I downloaded the app, and kept the  daily allowances at the preset amount, but could easily reset them to match the allowances of any data plan. Additionally, you can set the thresholds of the alerts it will send you when you’re getting close to you limit. It’s preset with 50%, 70%, 90%, and 100%, but can be changed to any percentages. Additionally, you can set it to sound an alarm when you hit those amounts.

I used my phone minimally throughout the next day. Early the next day I read an email and sent a text message, and checked to see how I was doing with my date. I only used one percent, so was still far from any worry zone.

Now it was time to see if I could do some damage to the amount of data usage percentage. I did a little of everything, other than watching videos or using the GPS, which I knew would really suck up the data. I checked my email and Facebook, used the map to plot out where I’m going over the weekend, updated my music playlists, updated three apps, downloaded a few magazine apps and a magazine preview to Newsstand, and played my favorite game a handful of times. It was less than an hour of usage. You can see on the screencap that I used much more data. Clicking the arrow on the amount for the day sent me to a link to see exactly how much was spent in both 3G and Wifi. I’m definitely over that 10 MB daily limit and am very grateful I have an unlimited data plan.

Clicking on the arrow next to the total amount for separate days will give you an exact amount of data that is used every step of the way. It’s almost a little frightening watching it laid out this way, and that’s from someone on an unlimited data plan.

Clicking the symbol in the upper right of the screen shows you the geotagging, where you were when you were using the data during the day. This map plotted out my house, as well as several individual spots several blocks away. I never left the comfort of my own home, so I’m not sure how it gathered that.

This is definitely a helpful app for anyone trying to keep a damper on their data usage to save them from paying an overage. For anyone who has kids with an iOS device, it’s even more helpful. While they obviously won’t be too concerned  how much data they’re using, that information can be made available to you if you can get their device away from them long enough to check. DataMan Pro (iTunes link)