Once you have it set up it's a blast to use! It's just a few plugins for JOSM and once you have the hotkeys memorised you can map out rectangular buildings in seconds!
Organic Maps thinks that F-Droid has it in for them. (Untrue).
F-Droid labels anti-features, properties of an app which are contrary to the philosophy of FOSS in some way. Organic Maps is labeled for two things:
Promoting a proprietary hotels website called Kayak, by inserting links to it when looking at any hotel in the app. This is considered promotion of a non-free network. OM did not like being labeled with this anti-feature.
Relying on Organic Maps's servers for downloading maps, without giving the user the option to change the server URL. This is called Tethered Network Service.
Tethered Network Service is a newly introduced anti-feature. This is besides the point, but before it was added, instances of this were labeled just "Non-Free Network Service", which was ambiguous and caused a lot of confusion. The important thing is that it's a new way to label apps.
The F-Droid app has a filter that hides apps based on their anti-features. The filter lists various anti-features to select, and an "Other" category for everything not listed. The new TetheredNet is part of Other.
Here's the problem: the default filter used to hide apps with "Other" AFs. This default was changed some months ago, but only for new installations. Old installations, even if updated, will stick to whatever was the default when they were installed, therefore they will hide Organic Maps. Organic Maps made a big deal out of this, basically trying to shame F-Droid.
According to the latest F-Droid news, this should be resolved already or soon. I don't know what the solution is, but I have a couple of guesses.
F-Droid do provide more detail about why they warn that something has an anti-feature, but only make that easily accessible if you run their code natively on your device. If you're on the web interface you have to figure out which of the links in the external links section isn't actually external and look in there.
Their excuse for this is that their website can't parse their own file format that they invented for themselves.