The easiest way is to start forever with /etc/rc.local. There are more complete ways to do this so that you can start / stop / etc ... or use something like monit (but this duplicates what it does forever).
You will also need to work forever with a non-root user.
start_forever.sh
cd /absolute/path/to/project /absolute/path/to/forever -m 5 examples/error-on-timer.js&
then to /etc/rc.local
sudo -u SOME_USER /absolute/path/to/start_forever.sh
source share