Django Python SQLite cross platform application. What to write on?

Question

Django

Hello.
Creating applications is new to me, so I'm asking for advice.
Given: A Django site using Python to process incoming user data and match it against the results in the database.
Task: Create (if possible cross-platform) application for mobile devices that works offline, launched NOT from a browser, Python must be used to process incoming user data and SQLite database
Question: Where to dig? What to write on?

Answer 1

PyPy