This thesis discusses the existing virtual communities within the application (app) market. Themain focus of this thesis is to discuss interactions between organizer (developers) and individual(users). The research question for this thesis was answered by interviewing several developers withdifferent roles in the field. Their answers showed that the user communities within the app marketare mostly pools as they share traits but members have no interactions with each other, and becauseof this the importance of the interaction between developer and user was highlighted. Additionally,the interviews informed us of the role other communities have in the development of apps, in termsof improving the apps before, during and after development.