After reading a lot of blogs and articles with all sorts of opinions about Core Data and my personal experience with it being very limited since I have worked in projects that used it but they were already setup and configured for it, I have also found some other 'apparently impressive' technologies like Realm and YapDatabase (I am always hesitant to depend on external companies/technologies especially if they are closed source).<p>About the data that will be stored, basically user accounts, like contact information: basic info (name, emails, addresses, phone numbers, etc.) and extended info (birhd date, other important dates, notes, social usernames, etc) and relationships between users.<p>If you have any experience with several of them, what would you use in a fresh start?