Skene Cloud and Skene for Ubuntu 22.04+ and Debian 12+ (Skene itself: Ubuntu 24.04+, Debian 13+).
sudo curl -fsSL -o /etc/apt/sources.list.d/synthtropy.sources https://deb.synthtropy.com/synthtropy.sources sudo apt update sudo apt install skene-cloud # or: skene
The source file carries the repository's signing key; apt installs only what that key signed.