A free app for Android, by D Apps Studio.

In the mood to prank your loved ones? If so, download Voice Changer : Audio Effects on your device and watch everyone roar with laughter. The app contains a wide variety of voice effects such as Robot, Chipmunk Low, Chipmunk Medium, Ghost, and more. Just tap on the microphone and you’re all set. It automatically saves voice recordings for hassle-free usage. 

All recordings can be used as a ringtone for calls or notifications.  This is good news for those who want a unique phone ringtone. You can share the audio with your friends and family should they want a copy. Overall, this application proves that you don’t need complicated software to change your voice.