Install GitHub Desktop on Ubuntu

wget -qO - https://mirror.mwt.me/ghd/gpgkey | sudo tee /etc/apt/trusted.gpg.d/shiftkey-desktop.asc > /dev/null
# if you want to use packagecloud.io
sudo sh -c 'echo "deb [arch=amd64] https://packagecloud.io/shiftkey/desktop/any/ any main" > /etc/apt/sources.list.d/packagecloud-shiftkey-desktop.list'

# if you want to use the US mirror
sudo sh -c 'echo "deb [arch=amd64] https://mirror.mwt.me/ghd/deb/ any main" > /etc/apt/sources.list.d/packagecloud-shiftkey-desktop.list'
sudo apt update && sudo apt install github-desktop

References
https://github.com/shiftkey/desktop