Hi Maxime,
FYI, this video can provide some background on the various ArcGIS Field App options that are available.
ArcGIS Apps for the field - YouTube (3 min video)
For more detailed info, watch this tech session,
Improving Workflows with Mobile Apps - YouTube
FYI 2, if you still want to create and deploy custom native apps, you may want to look into AppStudio for ArcGIS as an option. It enables you to convert your maps into beautiful, consumer-friendly mobile apps ready for Android, iOS, Windows, Mac OS X, and Linux, and publish them using your own brand to all popular app stores - no developer skills required.
Hope this helps,