Freeciv-web now has a new hotseat multiplayer mode. This is a multiplayer game where two or more players plays on the same device by taking turns playing the game. Wikipedia has some background about the game mode.
To start a new hotseat game, go to the main page of Freeciv-web, then click on the hotseat button, and fill in the player names.
Start a new hotseat game directly here!