Simply order your players, use the arrows to specify the number of players, and then click randomize! Then the number will be matched to a color depending on how many teams are selected.
Use the advanced settings to specify up to 4 teams, whether to include an odd number of people or have a randomly selected all-time player (only available for 2 teams), and the ability to flip a coin (Pigs or Peach) to choose things like who goes first.
Available on Wear OS.