Assessment of threat risks associated with a given mobile device application (app) on a device type specific basis, so that the threat assessment is specific to a particular device type that is suitable for running the given app. The assessed device-type-specific risk is represented as device-type-specific risk metadata, which is associated as metadata with the given app. For example, the metadata may be stored along with the given app in a common repository that includes many apps. In some embodiments, the device-type-specific risk metadata is generated and stored comprehensively for all apps and device types used in an enterprise. The device-type-specific risk assessment, and corresponding device-type-specific risk metadata, may be based upon run time behavior of the given app on a given device type.