This is my private Repo with Software I use, but either I can't find it in portage, or it's lagging behind in versions.

A few steps are necessary to use the Repo.

cd /var/db/repos
git clone https://github.com/sisihagen/portage sisi

Then need to make it usable for portage with a file in /etc/portage/repos.conf

echo "[sisi]" > /etc/portage/repos.conf/sisi.conf
echo "location = /var/db/repos/sisi" >> /etc/portage/repos.conf/sisi.conf

If you like to use layman to automate it:

layman -f -o https://raw.githubusercontent.com/sisihagen/portage/master/repositories.xml -a sisi

Now it's ready to use. Have fun with Gentoo Linux!