IP Track

IP Track shows all incoming and outgoing network connections of this computer
in a dashboard in your browser (http://127.0.0.1:8765): which program, which
site or domain, ports, timestamps and alerts for known malicious sites.
It runs in the background as a light system service and keeps a searchable
history. First login: admin / admin, then you choose a new password.

For complete monitoring connect the optional permissions once:
sudo snap connect ip-track:network-observe
sudo snap connect ip-track:system-observe
sudo snap connect ip-track:network-control