Winter Sports a showcase cross-platform .NET app available for iPhone users

Winter Sports, a comprehensive app for skiers and snowboarders is released for iPhone, powered by Microsoft cloud.

Winter Sports is an official app of more than 32,000 Professional Ski Instructors of America and American Association of Snowboard Instructors (PSIA-AASI), an educational organization teaching seven million ski days per season in the US alone. This cross-platform sophisticated app includes ski and snowboard-specific GPS tracker, snow reports and resorts maps from 2000+ ski resorts worldwide, as well as training, workouts and content for skiers, snowboarders, mountaineering enthusiasts and snow junkies.


GPS Tracker
Snow Reports and Resort Maps
Step Counter
Friends and Social
Training and Workouts
Action Photos
Ski and Snowboard Analytics
Worldwide leaderboards
Powered by Professional Ski and Snowboard Instructors of America

More about the app…

Cross-platform apps are becoming very popular with the users, who want to keep their data in sync on iPhone, Android and Windows. Also in line with Microsoft open source . NET Winter Sports became very popular on Windows Phone, grew to millions of users, and now reaches iPhone and Android markets. This app can easily be a showcase of Microsoft’s recent announcement for open-source .NET: a sophisticated native app entirely built with .NET and Xamarin.

Ultimately, with cross-platform apps, such as Winter Sports, Microsoft wins because the app is using Microsoft’s massive cloud technology called Azure, users win because they can use their favorite mobile device with the app, and developers win because the app works on all major markets: iPhone, Android and Windows. Developers also win, because they only develop one source code, with close to 95% code reuse for Windows, iOS and Android, according to Winter Sports developers.

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Azure Mobile Services and DateTimeOffset

Important update: Please, see a comprehensive post by Carlos Figueira that recommends two additional workarounds for this issue.

I ended up implementing a combination of my approach below and Carlos’ custom JsonConverter.

I use DateTimeOffset very extensively, my corresponding SQL Azure table in mobile services uses datetimeoffset(3) column. The issue that I had was somewhere during JSON.NET serialization, the DateTimeOffset lost the offset and got converted to UTC. I couldn’t find any solution, until I experimentally started playing with the Mobile Services Client SerializationSettings, exposed in the latest SDK. Changing DateTimeZoneHandling  didn’t seem to help much until I discovered this post by Carlos. I changed it a little bit, keeping the idea, and voila: my DateTimeOffset now saves in Azure Mobile Services, no problem. If you know a better way, please let me know:


                MobileService.SerializerSettings.DateTimeZoneHandling = Newtonsoft.Json.DateTimeZoneHandling.RoundtripKind;
                // remove date time converter
                var conv = MobileService.SerializerSettings.Converters.Where(c => c is MobileServiceIsoDateTimeConverter).FirstOrDefault();
                if (conv != null)