A free program for Android, by CH Mod, Inc..

Perfect Vocal is an app that will autotune your voice to the key of your choosing.

It features pitch and formant shifting functions, automatic formant correction, correction speed settings, automatic pitch correction, a selection of 48 keys, the option to re-process your recordings to different keys without the necessity of actually and manually re-recording the entire piece, the option to set your piece as your personal ringtone, a clip LED to inhibit microphone overload, and the option to share your masterpiece to your friends via social media networks.