Looking for a VPN Server

[Guest wasps]

Hi,

I've been running a VPN server at home on and off for a while now.

However, my VPN server is a virtual machine, which requires that I leave my VM host running when I'm away.

Whilst this isn't the end of the world, it's not particularly efficient.

I was wondering if there was any VPN server software that I could put on an old Android Phone.

I've looked at Servers Ultimate but that doesn't have a VPN server option, and I couldn't find any apps when I quickly looked through the Play Store

Thanks