My iPhone 4 data usage suddenly spiked. From using 30-40% of my monthly allowance in the average month (3-400Mb out of a allowed 1Gb), recently I used 175% (1.75Gb) in a single day.
I have to assume that they numbers from my carrier are more or less correct. The figure shown in Settings > General > Usage more or less tallies with their report.
There are a few apps (DataMon, etc.) which will monitor usage as a whole, but I'd like an app which can break down my usage by which app is consuming the data. (Ideally 3G vs Wifi too.)
Does anything like this exist - or can it even exist? My iOS coding skillz are not strong, and I can't think how I could do this, but that certainly does not mean that no-one else can.
NB. I'm not too concerned about challenging the figure, I trust it to be reasonably correct based on past performance, but I'd quite like to be able to monitor the apps and decommission those which seem to be using a disproportionate amount.