You can reverse play recorded sound.

This app records from microphone.
Then plays recorded sound or reverse play recorded sound.

First, record from microphone.
Then, play or reverse play recorded sound.

When playing audio, you can change
- playback rate (Range: x0.5 to x2.0)
- pitch by a half tone (Range: -2 octave to +2 octave)

This app can import an audio file from other apps by share action or from Files app.
Supported files: wav, mp3, mp4, m4a, aifc, aiff, caf, flac

Saved audio files are also accessible from Files app:
Files app -> On My iPhone/iPad -> Reverse Play -> Audio

Enjoy!

If you have suggestions to improve, just rewrite a review.
I will do my best!