This is a Debian/Ubuntu repository which distributes some apps. Currently, it only provides github-desktop.
Run following commands:
$ curl -sS https://apt.phanective.org/phanective.gpg | sudo gpg --dearmor --output /usr/share/keyrings/phanective.gpg
$ echo "deb [signed-by=/usr/share/keyrings/phanective.gpg] https://apt.phanective.org stable main" | sudo tee /etc/apt/sources.list.d/phanective.list
$ sudo apt update
$ sudo apt install github-desktop
github-desktop