Whistle is a free Android application developed by Infinite_Apps that allows you to have a simple whistle sound on your smartphone without having to spend money purchasing it in a retail store. This application is perfect for alerting people of your existence just by tapping your smartphone screen or waking people up from their beautiful sleep using a loud sound. With unlimited use, you can also explore many creative ways to use the whistle sound that has been lurking in your head waiting to be realized. The app doesn't complicate its interface with the things you do not need, so you can easily access the whistle sound with just one click. Enjoy using this simple and easy-to-use application!