A free program for Android, by Coolest Phone Apps.

Zombies are among the most frightening monsters in the world. You can find them in various forms, such as dead, living, and undead. If you enjoy the thrill of scaring people, then you should download the Zombie Voice Changer app. It has the most amazing collection of zombie sounds.

If you don't like the sounds of dead zombies, then you can choose from other scary sounds, such as a dead person, a monster, an evil clown, or a witch. Choose the sounds that you like.

This is a very easy-to-use app. You just need to record your voice with the microphone, apply the effects, and save it as a ringtone.