There are several. Unfortunately, they are all in early alpha. Lemmy wasn't quite ready for the mainstream, so the developers are scrambling a bit. That said, the improvements, even over just the last week or so, are impressive. Even if the apps are currently a bit threadbare and buggy still.

Jerboa is available on the app store. I'm personally using Thunder, though you need to download it from GitHub right now to use it. There are several more out there, but I've not played with them yet.