This documentation will help you to understand the differences between iViewer Licenses and LaunchPad credits.

iViewer 5 (and iViewer 4) can be licensed either via the legacy system or via LaunchPad. Both systems will take a Device ID and return you a license code to add to your guiDesigner project.

Once a device is licensed for iViewer, it can be transferred up to 3 times when devices are upgraded/replaced.

Any device that is licensed for iViewer can also be allocated to LaunchPad projects using the LaunchPad app using that existing iViewer license, without using another user credit. This is handled automatically when the LaunchPad system knows that the device ID has already been licensed for iViewer.
This can only work if you have installed iViewer already and licensed it before you install LaunchPad app on the device. Otherwise, if you delete the iViewer app before installing LaunchPad, the Device ID will be different and the existing license will not work to allocate the device to a project.

LaunchPad licensing is handled purely in the LaunchPad system and app. When a device running LaunchPad accesses a project, it can be either automatically or manually allocated to the project, using up a user credit from your account.

Once a device is allocated, it becomes licensed for that project, and can then be allocated to any other project without using up another user credit.

Then the device can be deallocated and the user credit returns to your account so that another device can be allocated in its place.

This deallocation requires the device to be either allocated in “online mode” or for the device to be reconnected to the internet so that it can be deallocated a project.

If a device was allocated in “offline mode”, then it can only be deallocated by returning to internet connectivity. If this is not possible, then it cannot be deallocated from the system and any further devices must use an additional user credit to be allocated to the project.