The default duration is 30 seconds but you can change the round duration in the settings. If the round is going on too long and the opposition team don't have any more answers, you can end the round early by tapping the countdown during the round.
Progress through a game is saved at the end of each round and can be resumed at any time from the home screen. Starting a new game will override the game that is in progress.
Categories! Doesn't offer used categories again after they've been picked for play but will reset all used categories if there aren't enough remaining for another round. You can reset manually from the app setting to bring everything back into play.
All of the categories were written by me the developer over the course of many years! If there are any you think I'm missing, feel free to send in a suggestion here.
Not yet but coming soon!