Pre version 1.1.0, the app is free and uses Googles Admob to display ads - and anonymous statistical information is reported to them so they can see whether their adverts are effective. Visit the AdMob site for more information.
From version 1.1.0, Google Admob is no longer used, the app is also no longer free. I felt it was better to charge and not allow Google to capture any information.
The leaderboard is managed by Apples Game Center.
No other information is captued in the app