Unfortunately for the first version I didn't track hours (I am now). It took all of last summer (June to August) of nights and weekends. Not too bad considering it was only a few hours per week b/c of being more active outside due to Summer. It's PhoneGap based, so much of the effort wasn't so much writing features so much as learning/figuring out the tools I used: KendoUI Mobile for the UI, PhoneGap Build for building native versions, and Knockout.js. I come from a .NET backend background, so I wanted the new challenge of building an app with frontend tech, not only for CSS/JavaScript practice but also benefiting from one codebase for multiple platforms (iOS, Android, and WinPhone 8).