Whistle, Red Card & Yellow Card is a free Android application developed by hosinoatusi. This app is designed to help referees of various sports such as soccer, futsal, rugby, handball, ice hockey, and volleyball. The app allows users to blow a whistle and display full-screen red and yellow cards.

The whistle can be heard for as long as the user presses the screen, making it ideal for referees who need to stop play quickly. The app's simple interface makes it easy to use, and the full-screen display of the red and yellow cards ensures that everyone on the field can see them. Overall, Whistle, Red Card & Yellow Card is a useful tool for sports referees looking for a quick and easy way to manage their games.