Please check the user manual first (EN/DE) and find the knowledge base and answers to technical questions in the FAQs of the former eBlocker GmbH. Mac and iOS users please read this article in case of certificate issues.
[Solved] Feature request: eBlocker on Raspberry Pi 4
I replaced a Raspberry PI 3 with a Pi 4 doing some entertainment stuff at home and it really speeds up some things .. I think the eBlocker would also greatly benefit from a slightly more powerful CPU, especially when using VPN, and more memory (2 GB should be enough). Also stability should be improved as memory limitations are in issue in some environments. Also, the Pi 4 CPU and appropriate Debian kernel may support hardware encryption as well.