A free app for Android, by Pierfrancesco Panunzi.

This is an EVP (Electronic Voice Phenomena) recording and playback app that can record the voice of ghosts or spirits and play it back to you. It is an audio recorder that has three preset voices: “I’m here”, “My name is Jhon.”, and “Aha”. You can record your own voice or use one of these pre-recorded voices to create a story. The sounds must be saved to the folder “ghost” in your device’s memory card. Every time you record and then play the sound, it will appear after the set delay.