If someone annoys you, give him the Yellow Card. If you want to kick someone out, give him the red card. It's strong and simple communication tool. When you shake your card, it whistles.
Useless Lab. is the developer of this application that can be found in the Communication category. The most recent release was on Dec 29, 2011 and the app was downloaded and set up by over 5K users. Yellow Card has been rated 4 on Google Play.
There are adverts in this application. Take the opportunity to get the setup package of Yellow Card 1.1 free of charge and read users' reviews on Droid Informer. The app is built for Android 2.2 and higher. The download of the app is 100% safe.