Yeah, I’ve tried, both for actual files and for tracking my reading across multiple platforms, and nothing really seems to fit my needs, especially when I want to actually read them on an Android ereader. Anything I choose seems to have a lot of manual effort, frequently, or just a dumpster fire of an actual reading experience.
I feel like I’m eventually going to have to make my own, which is fine, I guess, but I’m definitely not comfortable actually managing a community project or just building up the codebase or documentation to the level someone else would be enthusiastic to use as a jumping off point to manage themselves, so it will probably just stay a personal project that ends up not helping anyone else solve the same problems I have.