Hi,
Regarding your questions:
1. Is Developer required to purchase application Runtime License for every application distributed? For example, we develop an app and want to distribute it to 10 devices, do we need just one developer license and then we can distribute as many as we can? Or we need license for each device i.e. 10 licenses?
Yes, as the developer you are required to license every application you deploy. In your example, the app deployed to 10 devices requires each of the 10 app installations to be licensed for deployment. Licensing can be done via:
- An ArcGIS Named User where the user of your app signs into ArcGIS Online or Portal for ArcGIS to unlock `Lite` as a Level 1 User or `Basic` as a Level 2 User.
- A license key that you compile into the application. Note that license levels Standard, Advanced, and Analysis are currently only supported with the license key approach. When you receive a license key (string) to license your app, you use the same license key each time you deploy that app and you are required to keep track of how many times it is deployed and purchase the appropriate number of licenses.
2. Please elaborate this "per app/per device".?
The term 'per app / per device' means each application you deploy to a single device must be licensed. Effectively there is no device-wide license for multiple installed apps. As above, you can either license the app via the Named User approach where the user of the device would sign into each application on the device or license the app using the license key approach.
Resources:
License your app—ArcGIS Runtime SDK for .NET | ArcGIS for Developers
Levels, roles, and privileges—Portal for ArcGIS (10.6) | ArcGIS Enterprise
Cheers
Mike