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I currently use MyDataUsage. Icon has a green up arrows and a red down arrow. I like it since it I can track both cellular usage and wifi usage. Just put in the cycle date for your carrier and it tracks all usage. :)
 
I use the My Verizon app, or if you're on At&t, use their app. Both is the best apps to tell you data usage since thats who you're getting the bill from. Plus you don't have to restart you data cycles or monitor anything like that.
 
I currently use MyDataUsage. Icon has a green up arrows and a red down arrow. I like it since it I can track both cellular usage and wifi usage. Just put in the cycle date for your carrier and it tracks all usage. :)

Should mention too that it is iPhone and iPad compatible. Makes it nice to track and see if a shared plan would be better cost.
 
I use the My Verizon app, or if you're on At&t, use their app. Both is the best apps to tell you data usage since thats who you're getting the bill from. Plus you don't have to restart you data cycles or monitor anything like that.

Down side of the carrier apps is that they are measuring estimated data usage and not the actual data transfer across your phone. This means that the usage shown on the carrier apps is about 24 hours behind your actual usage.

Personally I like to use both the Verizon app and the cellular data usage reported in settings. I have an app called dataman but haven't used it much yet.
 
I use the My Verizon app, or if you're on At&t, use their app. Both is the best apps to tell you data usage since thats who you're getting the bill from. Plus you don't have to restart you data cycles or monitor anything like that.

I can't get the myATT app to work. Can't log in with my Premier acct
 
actually, when you log in to the AT&T app on iPhone it will say for example "data usage current as of 10/11/2012 at 8:00pm"

If you are on AT&T you can also text *3282# for data usage but it's not as accurate as the app itself
 
I'm using DataWiz. Free, and shows you daily totals. You can see your data ticking up in almost real time.

That app is sneaky. I don't know if you noticed but it has a built in SIP VoIP client. This is their way of getting around Apple's restriction that apps can't run in the background, because VoIP apps are exempted from this restriction.

I have a feeling Apple is eventually going to catch on and pull it from the store, because it's basically trying to cheat the rules. Also it burns battery so be aware of that.
 
I guess these apps need to be running all the time right? Wouldn't this just be a battery killer? Just asking.
 
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