Adhell3 is merely an app that is using the Samsung Knox SDK APIs.
In order to use these APIs, the Knox SDK and an ELM Development license key are needed.
These are Samsung's properties which are not available in this repository and therefore they need to be downloaded and obtained by the developer after accepting the agreement given by Samsung.
The original Adhell was developed by Samsung's developer. After he was forced to remove the code from internet by Samsung, FiendFyre was stepped up by providing the Adhell2. But after a while, it is also discontinued.
Adhell3 is an extension of previous discontinued Adhell2 app with more additional features.