Cross-platform development, simple mobile app, short deadline

I am looking to develop a very simply mobile app, a "content distribution" app. Think of it like the CHM files in Windows (files that store the "Help" data in programs). Or think of it like a mini-version of the Wikipedia app.

The app:
- contains "articles" with text and some images
- articles are organized in a hierarchical form based on topic
- desirable (but not required): there is a word-search function in the articles
- very desirable: the app can work offline (no network connection)
- very desirable: when connected, the app can download new articles from a server.
- very desirable: localization - the articles will come in english, russian and chinese, and the end user should be able to choose his default language - and see the appropriate articles.
- required: the app works on iOS devices, Android phones and tablets, and (potentially) Windows Mobile.


The catch:
- I have limited programming experience (C++, LAMP, Python, VB)
- I have 2-3 weeks to build the app with about 20 articles in 5-6 languages (or at least a strong proof-of-concept app)

The question: A google search shows there are a number of cross-platform development tools (PhoneGap, Appcelerator, Mosync, Widgetpad, Whoop, RhoMobile...). Considering the requirements and the limited timeline, should I use any of these? Another tool? Is this even doable?

Or is there an open-source app or framework out there that I can modify and build upon?

Note: The ability to download new articles may require developing a back-end, making the project much more complicated. Therefore in a first version I am open to making it easier: pre-loading the app with a set of articles, no option for downloading new articles when connected.