Help me develop project todo process...

I've been on the quest for a project management app for months.

The paradox I can't solve is that I can't find a full Linux app that also works and looks great on Android. I'd like to store my project files locally, not on some cloud app on Amazon that will shut down or get bought 2 - 3 years down the line.

I looked at project libre, but no Android support (or at all, for that matter, it looks kinda dead). I looked at something more traditional like folders and text files, then sync with syncthing, but working in text files doesn't allow me to capture stuff nearly as well as I do with something like keep, where it's super easy to capture pictures or quick thoughts without futzing about in some folder deep in my phone.

At work I use onenote. It does everything I need, captures it all well and then I can sit and organize my ideas further... But of course, Microsoft has my shit on a cloud behind a TOS. don't want this with personal stuff.

I have a wiki (tiddly wiki) which is awesome at organization and keeping everything wherever I want it... But it sucks on the phone and I can't capture anything with it quickly.

I even went as far as developing a procedure where I capture with Google Keep, then sort stuff out when I got the time, but rhen I don't have the sorted out info available in the phone anymore... Ughhhh!

Help. I'm going banans. Obviously I'm over complicating things. Help.