Frustrated by the currently available indoor tools I made an OsmAnd theme.
Direct download link https://raw.githubusercontent.com/karliss/osmand-indoort/refs/heads/main/indoor_exp.render.xml
Also made a blogpost, but that ended up being more about technical details of how OsmAnd themes work less about the indoor theme itself.
Make sure to read either blog post or the README for the list of limitations (there is a lot of them).
Works best with something like a university building or mall. Not so much with complex train stations.
If you have any questions or examples of interesting places that have indoor tagging and works well or badly with the theme feel free to ask here.
Screenshots with some examples:



