The primary application to date has been military (i.e. nuclear weapons).
If disease is prevalent after primary application, a second application 14 days later may be necessary.
And the age of the primary application should be at least 20 years.
Hugin can be used to correct distortion, though that is not its primary application.
The primary application for Li-air battery development is in automotive.
The primary application is to combustion and fire research.
The primary application of linear least squares is in data fitting.
The primary application of this technology is to provide in-chip performance tuning.
Of course, many users may stick with their primary applications and never explore other features.
One of the primary applications will be imaging radar.