deltafeed used to be a loginless/sessionless service in its beta state, serving as a functional testing stage.
For the beta users:
if you were using deltafeed in its previous open version without the registration: just get an account and you will get a way to fetch your own feeds into that account…
your feeds stay online for rss-readers, so if you still remember/saved the urls of these feeds, deltafeed feeds them with latest monitorings (as long as you keep pulling these deltafeeds).