There are many very good HTTP-log analyzers like AWstats,
The Webalizer or Analog,
just to name a few.
mobile-usage (the tool which generated this statistic) is not a full-blown log analyzer, just a supplement to existing ones with a special focus on mobile devices. It should give you answers to questions like:
- How many visitors come to my site using phones or tablets?
- Which mobile devices are used?
- Which mobile operating systems and versions are used?