I actually figured this out about a month ago.
1. Create web application. You can use vanillajs or any framework of your preferrence (react, vue, svelte, angular, etc).
2. Make a production build of your project (dist files/static files).
3. Make an app.json file, add it to the root of your project and use the following structure:
{
"id": "whack-a-mole-game",
"name": "Whack A Mole",
"icon": "imgs/mole.png",
"description": "A Whack A Mole web game"
}
4. Drop your project folder (the production build) to /www/apps/. Also, I usually renamed it with the prefix oos-app-, I didn't look too much into it, so I can't tell if it's necessary or not to recognize the app.
It is possible to run django on the omega, as the omega can run python 2 & 3.
It is also possible to implement a webserver in your custom application. You just need to understand that the way custom applications are displayed is due to an HTML component called <iframe> which fetches and runs embedded web applications retrieved from the provided src attribute.
Hint: The src component can be a server endpoint which serves static files. I have never tried it, but I'm almost positive it should work.
