Sound Changer, a music player for Android, allows you to set a new ringtone every time a call comes in. The sound will change every minute, so you won't be able to predict what you'll hear when you pick up. It's perfect for when you want to get your friends and family members' attention, but don't want to scare them away. It's also useful when you need to make a specific sound, like when you need to notify someone or when you want to get their attention. You can also use it to change the ringtone for your notifications.