MasterPDFEditor: 4.3.89
This is version 4, which still saving without a watermark from the trial version.
If you are looking for the latest version of the program:
https://github.com/ryuuzaki42/MasterPDFEditor_AppImage
Based on: https://github.com/area-of-dev/Master-PDF-Editor.AppImage