Back in July of 2013 I released an app called Line Diet for iPhone written using Xamarin.iOS. A few years later an iOS update broke my custom implementation of entering a weight, so the app stopped working (as I had no time to fix it), and I pulled it from the App Store. Since then I've intended on re-releasing it (and even had a personal version with nearly complete Apple Watch support), but since this was more of a personal interest app, and not one that was generating revenue, it sat on the back-burner for the last year or two.
Today I'm happy to announce that not only is Line Diet back, but it is now available for both iOS and Android. On top of that, it is now an open source project on Github. It is written in C# and XAML using Xamarin.Forms, Prism, and OxyPlot. While the app is pretty straight forward, it has some pretty neat features as well (dynamic color theming, MVVM architecture, graphing, etc.). My hope is that it serves as a good sample app for folks looking to learn MVVM based mobile app development using C#, Xamarin.Forms, and Prism. It has plenty of potential extension points as well, so feel free to submit a pull request if you have interest in adding to the project.
You can find out more about Line Diet and find relative app store download links at LineDietApp.com.