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Tangentially related - we did some analysis a little while ago of how screen size affects use behaviour (in terms of data consumption) - http://opensignal.com/reports/data-usage-by-screen-size/

What did you use to create those charts?

From the HTML source, it looks like these graphs are from D3.js - http://d3js.org/

one gold star to you! Yes, it is D3.