Improv Tools has suggestions for one word, a place, "how they know each other", an object, a "problem they're trying to solve", and an unusual event!
It also has a list of common short form improv performance and warm up games to give your improv team or class fresh games to play with.
Lastly, Improv Tools provides a refresh list of "rules" to get you out of your head and back to basics. There's also a timer in case you choose to play a timed game.
App Screenshots
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