The official answer is that the Nebulb license is personal and is associated to a specific email.
To this email Nebulb sends, for example, the code needed to change the license password (for security reasons, so that no one else than the owner of the license can change the password).
And the “unofficial” answer is that we cannot control (nor do we intend to) on which devices Nebulb is installed and used.
The license allows Nebulb to be installed and used simultaneously on 2 devices, whether those two computers are owned by the same person or by different people.
And once Nebulb is accessed for the first time on the first two computers, it is no longer possible to access Nebulb on computers other than those two.
That said, in case you need to renew/change any of the computers to which the license is assigned, there is no problem either. You send an email to firstname.lastname@example.org indicating that you want to change the computer on which Nebulb is installed and we will reset the license so that you can change the computer and install and use Nebulb on the new computer.