Reverse Talk lets you record and then play it backwards or forwards. Playing something backwards usually results in something quite amusing. Some say it reveals hidden messages in lyrics. Babies sometimes speak backwards, although most parents seem unaware of it.
Reverse Talk has the following names in the localized App Stores:
NL: Achteruit praten
DE: Rückwärts reden
FR: Inverser parler
Great fun for a fraction of the price of a cup of coffee: $0.99.