Five Filters has a paid service, but they also have a free docker app for people who want to self-host. https://github.com/heussd/fivefilters-full-text-rss-docker
That container is running PHP5. Make sure to either not run it public or to properly secure it.
Backed this on Kickstarter. Seems honestly too good to be true, so I am antsy to get my hands on it.