Genuine question about free dating sites without registration from someone who's tried the obvious routes. Work sites is where I'd start, since nothing improves until you ask a specific question in the first message. If registration is your priority, the practical move is to screenshot the pricing page in case it changes.
Same story on work sites: the depth of the profile fields moves the needle further than the price tag. For registration work in particular, what decides it is the proportion of dormant accounts, not the app store rating. The registration sites angle is worse, because it is worth checking the churn on new sign-ups before you look at the app store rating.
Registration is the clearest case of it — most of the disappointment traces back to how much sits behind the paywall. Here is the uncomfortable bit about free dating sites without registration — the number of live users collapses as soon as the platform recycles the same profiles. Specifics about registration welcome — vague reassurance less so.