I would think that is proprietary info to the traffic carrier.
Actually, no. It's tracked by various organizations such as NetApplications.com, who track the number of hits on various websites.
iOS Users Seven Times More Active Than Android Users, Suggests Net Applications
Two numbers from recent surveys on ‘share’ in the smartphone world nicely illustrate the difference between users of the Android and iOS platforms, and act as a reminder to place Android’s market share dominance in perspective.
As Android touches 85% of the market share in terms of handset sales (see this week’s Android Circuit), iOS sits at 11.9%. Android is just over seven times more prevalent in Q2 2014 than the next-best platform (iOS). Which makes the data from Net Applications on the usage share of the two platforms even more of a contrast.
This may be the first time that the Android platform has overhauled iOS in terms of usage (as measured over their own network of customers using Net Applications for their live statistics) with 44.62% against 44.19%, but it still shows that iOS users are more active online, which in turn will generate more revenue generating opportunities for those targeting mobile users.
Q2 2014 Mobile OS Usage (Data provided by Net Applications)While most mobile advertising networks will allow marketing teams to target all the mobile platforms, anyone looking to target a specific platform, especially developers, should consider these numbers carefully and in context. Any survey is going have some margin of error, but the trend of iOS users being more active than Android has been consistent over many studies.
While it is true that Android is picking up more active users (and therefore more valuable users), this is a very slow process. Because of Android’s reach into the low-end handset market, it’s unlikely that Android will ever get close to parity with iOS in usage surveys because of the volume of users who just want ‘a phone that works’ and then pick up an Android handset by default.
This is one more reason to take the overall market share numbers with a pinch of salt. Not all users are equal; not all handset sales will contribute to a larger audience for your application, advertising campaign, or freemium game title; and targeting the biggest platform will not guarantee you the biggest result.— Source: Forbes Magazine—by Ewan Spence, 08-03-2014
Funny thing is that Android users are high-fiving each other over finally getting a percentage higher than iOS in net-usage. . . but ignoring that it takes all 225 Android makers' devices to overcome ONE iOS maker's devices when they outnumber that maker's devices by seven to one in market share. . . but can only finally equal iOS in net-usage after all these years!