The build status is failed as it's using Windows Phone 8.1 Framework, which is not anymore supported by Microsoft and Visual Studio App Center can't check for it anymore.
"Calculateur de pourboire" sur Windows Phone
- Download and install Visual Studio Community.
- Download all the files.
- Place all the files to your documents, in Visual Studio folder, Projects and create "TipCalculator" folder.
- Click on TipCalculator.sln
- You're ready !
If you juste want to test the app, it's available on the Windows Phone Store !
https://www.microsoft.com/fr-be/store/apps/calculateur-de-pourboire/9nblggh0dth4
Current version : 2014.1223.1331.135
Not currently available on all stores and only in french (for the moment). App officially released for Windows Phone 8.1