Have a app where you can create, view and playtest your own decks while not being connected to the internet.
Adminaxpendix (Creator, TCG ONE) commented
Offline versions are hard to update and maintain, why would you want that?
You could launch an offline version of the simulator with support for lan connection
This would be ideal as he could play without ever having to really go to the site.
If possible make it so this simulator can be downloaded. Playing in browser can be difficult and some users can't do that. Having both options would be nice