I've updated the web application so that it now allows the user to log in as a Player or a Gamesmaster. As a Player the user can select a GM from the list and roll three characters in that world. Those characters will show up in the Gamesmaster's Freepool list. It is probably a good idea to not have very many NPCs in the Freepool, but instead assign them to an adventure group. This way you will see new characters as they get created and be able to recognize them as such.
When the Player upgrades to Gamesmaster they can then create a World, and now roll NPC Characters, and manage their world. If the Gamesmaster downgrades back to Player again, he can now access his Characters in other GM's Worlds. This way the Player can not roll a Character in a GM's World and then upgrade to GM in order to manipulate the stats of that character.
In effect you can now switch back and forth from being a Player to GM and manage your world, and still have Characters in other GM's worlds with a single logon.