Inspired by
these two threads I have been working on some things for tiddlywiki that act like menus in mobile apps. I have one of the types of menus mostly working, there is a demo of it
here.
Some stuff:
The menu 'remembers' how you got to where you are in it, so you can navigate backwards to retrace your steps
The menu can be built to an arbitrary depth
It uses the same sort of tagging hierarchy as the table of contents macros
Getting the template it uses to work may have broken my brain. I went from the simple example from before with 5 or 6 tiddlers needed to make it work, to a working version of what is there now with about 20 tidders needed, to 2 relatively short tidders needed now. It is 60 lines of wikitext total and despite the fact that I just spent the last few hours making it I don't think I could tell you how it works. This isn't really relevant to anything I just thought I would share.
Someone (or possibly multiple people? I am not sure) had asked about a way to navigate backwards through a table of contents following the same path you took forward. Being able to do this is an accidental side effect of how I made everything else work. It may not be exactly what was wanted, but I never did get the requirements for whatever the request was about.
I am probably going to be working on this more tonight, so things may change soon.