Looks like a decent program. Needs Chromecast for easy projection. Google wear support would allow referee to easily control display, where carrying a phone and aces sing it is hard.
I like this app
Great for many games I use it for my pool tournament. I switched to the $1.99 version which has 7 scoreboards and no ads. Highly recommended
Keep scores and time for different sports and games, soccer, basket, athletism..