What is the best app for managing data usage on an iPhone 4S?

Not using any app, because no app can manage your data usage.

There are multiple ways. If your iPhone is using AT&T you can download their app to check on your data. if you are talking about iPhone Ddta rather then texts, emails, GB/MB/KB. Go to settings-----> General-----> About

That doesn't "manage" your data usage - it simply reports what you have used.

Julian Wright wrote:

Not using any app, because no app can manage your data usage.

Slightly incorrect. Go to App Store on iPhone ----> Search ------> type data Usage ------> Most popular App called Date Usage. Priced at $0.99. it is unversal and will tell you everything. there are also about 20+ Apps also

As I said below, those apps only report your usage, not allow you to manage it.

No app can manage the data usage of your phone because no app has control over what data any other app uses. Those apps won't prevent you from going over your allowance by managing your phones data usage. You've still got to manually watch what you're using, whether it be a third-party app or the built-in usage report.

wait Is he talking about "Celular usage" or iPhone Data---> Music, apps etc??

LOL you guys are hilarious. OP just wants to see what is using what for data on the iphone. fail troll is fail

Assuming that DonXX means 'monitor' rather than 'manage', my experience may be of relevance.

I have a data usage problem with my iPhone 4. It started for me when I 'upgraded' to ioS 6. This may or may not be a coincidence. I went from an average monthly data usage of 150MB/month (a 2 year average) to 8.1 GB up/download in 28 days. To try and track down which app is The Ravenous Bugblatter Beast of Traal, I've just installed the Onavo Count app. This claims to monitor the data usage of each app. My sights at the moment are on Skype. I only use iCloud for Calendar syncing.