I used some contact apps in the past years, but always become frustrated with privacy, usability and features. Sometimes I found an app that seemed good enough only to see it acquired and shut down some time later. In fact, I was working on a contact app in a hackathon in 2011. I always thought the people in our life matter a lot and that good tools can help us.
What followed is a lot of user research, prototyping basic interfaces in Keynote and discussing the prototype designs with friends.
Eventually I started working on the iOS app.