Today loss and data protection are main concern for organisations.
So, all the mobiles devices need to be authorised before getting access to enterprise data.
If the user is internal, he can install all available client (Apps, Windows Client).
The idea, would be to get all the devices waiting on quarantine before letting them access to the entrerprise data.
It must be an option you can activate or not for smartdevice and desktop client. The device must be lock by an internal unique ID. By that way User can only use Filr on approved Devices.