Is Apple's App Store a cellular data hog?

iPhone and iPad wireless subscribers may want to think twice about searching for and downloading new apps from the Apple iOS App Store while on the go.

It's no secret to iPhone and iPad users that watching movies and listening to streaming audio consumes the bulk of their wireless data plans, but what may surprise them is how much data they eat up looking for and downloading apps from Apple's iTunes App while on the go.

Onavo compiled a report of the apps that consume the most data on iOS devices. Onavo

A recent report from Onavo, which has developed an app for tracking data usage on iOS devices, indicates that simply looking for and downloading apps from Apple's iOS App Store can chew up about 13 percent of all data consumed in a monthly data plan.

The company analyzed 8 terabytes of data it has gathered anonymously from iPhone and iPad users who have downloaded its app. While it comes as little surprise that the No. 1 data hog on the iPhone and iPad is streaming data and audio, usage of Apple's iOS App Store came in third place right behind Web browsing.

According to the report, the App Store accounts for more than 13 percent of all iPhone data usage in the U.S. each month. Three quarters of that data comes from downloads, while 24 percent is attributed to searches within the App Store.

Watching movies and listening to streaming music services, such as Pandora, accounted for about 35.3 percent of data consumed. And Web surfing ate up about 17.1 percent of usage.

Another surprising tidbit is that Facebook, which many people might assume consumes a good chunk of a monthly data plan, wasn't even in the top five apps that consumed data. After video and audio streaming, Web surfing, and Apple's iOS App Store, Google Maps consumed 8.3 percent of data, while e-mail consumed about 4.0 percent of total data. Facebook ate up only 2.8 percent of the total data for the month.

Onavo's report is interesting because it sheds some light on how real wireless subscribers are using their data plans. Understanding which applications are used most often and consume the most data is very important for consumers as wireless operators eliminate unlimited plans in lieu of usage-based data plans.

"Most people are blissfully unaware the App Store is hoovering up their data plan," Guy Rosen, co-founder and CEO of Onavo said in a statement. "iPhone users should be much more careful when downloading their Angry Birds--it's something best done at home, within the safety of Wi-Fi."

An Apple spokesman did not immediately respond to a request for comment on Onavo's report.

AT&T, which had the exclusive contract to sell the iPhone in the U.S. until February this year, was the first major wireless operator in the U.S. to move to a tiered offering for its smartphone customers. Verizon Wireless, which began selling the iPhone in February, discontinued its unlimited data service for new smartphone subscribers in July.

T-Mobile USA still offers an "unlimited" data plan, but it has begun limiting how much data its subscribers can use by slowing down service after customers hit a monthly usage threshold. AT&T has adopted this same plan for smartphone subscribers grandfathered into its unlimited data plan. And as Sprint is rumored to be getting the iPhone 5 when it's launched next month, there are some who speculate the carrier may ditch its unlimited data plan to ensure it can handle the anticipated traffic load associated with the iPhone.

Wireless operators that have put these data caps in place say that only a small percentage of their users actually exceed the defined limits. And data from companies, such as Validas, which tracks smartphone subscribers' data usage, backs up these assertions. In fact, most wireless subscribers are over-paying for data. And wireless operators say usage-based data plans are necessary to ensure that a small minority of customers don't consume more than their fair share of resources.

But one thing is clear, usage is increasing. Validas issued a report this summer that said Verizon Wireless customers have increased their usage by 150 percent over the past year. AT&T subscribers have increased usage by about 116 percent. What may be unclear and confusing to smartphone wireless subscribers, however, is what applications are actually eating up that data. Onavo executives say that is a key question that they can help consumers answer.

"Data addiction has taken hold across America, with U.S. smartphone users spending $55 billion a year," Rosen said. "Our monthly reports shine a light on where this money is going, so people can make informed choices about their data usage and save money."

Onavo has developed apps for the iOS devices as well as for the Google Android operating system. Primarily, these apps track and record how much data individual users are consuming. And they provide subscribers with the data in easy to read formats. The iPhone app also compresses certain types of data to help wireless subscribers conserve their data plans.

The app is available for iOS and Google Android devices. But the iPhone and iPad apps, which were developed before the Android app, also compress certain data to help subscribers' conserve bandwidth.

Based on the data from its first report, which included only usage from iOS users, Onavo came up with five tips to help consumers cut their mobile data bills.

Tip 1: Don't shop on the go

The App Store is one of the major drivers of mobile data--download your songs and apps at home over Wi-Fi, which is not counted in your monthly data usage plan. And Onavo experts say you save as much as 10 percent of your data.

Tip 2: Switch e-mail to manual

When e-mail is set to "push" your device is constantly checking for new e-mails and downloading them automatically. Change your settings to "manual" and get e-mails only when you want them.

Tip 3: Use mobile Web sites

Many Web sites have a mobile version which use much less data. Instead of www. try typing m. before the address instead.

Tip 4: Compress your data

Download a free app, such as Onavo, which can compress your data. The company claims it can save users as much as 80 percent of your data usage. You could also download and use a different browser, such as Opera Mini browser which automatically compresses Web pages.

Tip 5: Stream and download movies only when in Wi-Fi The biggest data hog is streaming videos. So instead of watching a movie over a 3G or 4G wireless network, make sure you're in a Wi-Fi hot spot.