Putting this to the room because which free dating apps that actually work have is where I keep getting stuck. The algorithms apps case is instructive — the practical move is to give it a fortnight before judging the pool. Algorithms work is the clearest case of it — how well it works on a weak connection beats the number of features listed.
For algorithms apps in particular, the signal-to-noise in search outweighs raw member count, with the usual caveats. Algorithms work is where I'd start, since it is worth checking how quickly the inbox fills before you look at whatever the landing page promises. If algorithms work is your priority, the deciding factor is the time it takes to get a first reply, as far as I can tell.
The algorithms angle is worse, because half the frustration disappears once you run a reverse image search on suspiciously polished photos. Most threads about which free dating apps that actually work have miss this — the platform resets your filters after an update, so it pays to use a photo that appears nowhere else online. Anyone who has tested algorithms properly, please weigh in.