Downloadable additional content inside the game.

Hi, I am trying to figure out a way to add downloadable additional content for my game. For example suppose there is a menu to select the Level at the start of the game, and in future I release more levels for the same game, is there a way that those new levels appear in the menu and a player can choose to (or not) download those new levels? I would prefer to host these new levels on my own server. Thanks