Hi Jose,
> What is the most useful operating system?
We support iOS, Android, and Windows. Not sure what you're asking by "most useful" as it really depends on the organization's/individual's choice of device.
> When will they release a new version?
The next release of Collector for ArcGIS (Aurora) is planned for Q3 (iOS) and Q4 (Android) respectively.
> And, What are the future development plans?
Please review the contents of this thread, https://community.esri.com/community/gis/applications/collector-for-arcgis/blog/2017/09/06/the-auror...
Hope this helps,
