Web-development – How would you create a mobile (android) offline wiki site

My apologies in advance if this is not a good forum for this question; pointers to others happily accepted.

On the off chance it matters, I'm not going to commercialize this idea or anything; if anything in here is interesting to you, use it as you see fit.

My basic problem is this: My favorite place to do non-code writing (essays, fiction, etc) is on my Android phone when I'm traveling. Said traveling often causes the phone to lose all signal/web connection. I would like a system that auto-syncs with the phone in some fashion, can be written in a fairly wiki-ish style (i.e. links are supported but I don't have to actually type out also be edited easily at a regular computer when needed. I'd prefer the editing on the phone be as close to plain text as possible, because fine manipulation like that required to set something to bold or whatever is a pain; I'd rather just be able to type things out.

Nice-to-have is the ability for other people to collaborate on documents. Very-nice-to-have is authentication so that some documents can be private, without having to get into the auth quagmire myself.

There really doesn't seem to be any such thing out there.

The two options I've thought of for implementing this:

1. Now that there exists a proper 2-way sync dropbox app ( https://play.google.com/store/apps/details?id=com.ttxapps.dropsync ), I could just use a plain-text editor on the phone and have a simple web app that presents the text via a wiki markup library of some kind out of the relevant dropbox folder. Advantages: Dead simple. Disadvantages: No easy auth or collaboration.

2. I could use Google Docs, and have a not-so-simple Web app that pulls documents from there, treats them as wiki text, maybe does some cashing, and presents them as a coherent-ish web site(s). Advantages: If I can get the auth to pass through properly, auth and collaboration are free. Disadvantages: Much more complex, and this is just a one-off personal project.

I'm curious as to whether I've missed anything, any other easier ways to solve this problem. I'm actually a little surprised that no-one seems to have thought of backing a wiki on Google Docs; there's the Google app wiki stuff, but that pretty much requires a browser AFAICT, whereas there are several Google Doc apps on pretty much everything with offline sync options.