My favorite Reddit client Infinity has a Lemmy version now, it’s still heavily WIP (pre-release) but works like a charm already. A few hours ago IzzyOnDroid added it to his F-Droid repository so while it’s not in the official one yet, which isn’t that easy with a pre-releases app and only updates weekly, you can install and update it thought your favorite F-Droid client now! If you use F-Droid you should have Izzy’s repo anyway, otherwise you did something wrong! ;)
This should be enough but if you have issues adding his repo I recommend to get Aurora Droid, it’s a beautiful F-Droid client and has a list of useful third party repos you can enable with a single click!
Edit: some more useful links to check!
Can I download and install aurora Droid from your link if I already have fdroid installed on my phone?