A free program for Android, by Pandaky Apps.
Creepy Voice Changer is a free application for recording, editing, and playing with audio and video. It lets you make scary noises and voice changes, which you can then send to your friends via social networks.
If you want to scare them, just click on the button to record a new sound, choose the effect, and record it!
You can also use the app to make some funny jokes and sound effects. Just click on the button to make a sound, and the app will automatically record it. You can edit the sound, add effects, and change the pitch.
To finish, you can also add some music to your recording. You can choose the music from the app’s music library, or you can add your own music.