How are smartphone data collected?

We use the following user-agent to collect the smartphone data:

(Mozilla/5.0 (iPhone; CPU iPhone OS 7_0 like Mac OS X) AppleWebKit/546.10 (KHTML, like Gecko) Version/6.0 Mobile/7E18WD Safari/8536.25)

For the smartphone data we crawl the top-100 results, just as for the desktop data. We collect this data for all countries available in the Toolbox. We crawl the keyword-set of the German Visibility Index (250,000 keywords), as well as that of the rest of the world (1,000,000 keywords) once per week.