I attribute much of the success of my solitaire game to the fact that I chose to build an "unsexy" app that I felt pretty sure had a market rather than a "sexy" app where the market wasn't as clearly defined. The first solitaire app I built was for the Mac App Store. Ten years ago, and still, today to some extent, the competition on the Mac App Store wasn't as fierce as was on the iOS App Store. I decided that I wanted to try and build an app that could generate some side income for me, which was kind of the main criteria for this little venture.