Do people in your circles/contacts see your downloaded apps in their recommendations? is your app/movie/book history available to people in your circles/contacts by means of recommendations or some other way
App Recommendations in Play Store are based on different criteria. But, overall one can say that the following are some of the things which google takes into account when showing the recommendations to you or your friends,


You/Your friend +1'ed an item on the Playstore.
You/Your friend rated an item.
Some recommendations are based on locality.
Items that you have already installed/bought with your google account.
Items that are top rated in different categories like Games, Apps, Movies, Music, Books etc.