You can use this app in two modes.
Simple mode : record your voice and playback it.
Fun mode : are you sure you can easily repeat what is said backwards ? ;)
In this mode can play two.
Second player covers his ears, when first player records any word or phrase, for example - "Hello brother".
Thereafter, second player listens to the reversed word or phrase that the first player recorded - "Rehtorb olleh" - and tries to repeat it.
Player's goal - say as accurately as possible.
After the second player recorded himself, listen to both version - the recording of the first player in "normal" mode and the record of second player in "reverse" mode.
Compare - does it sound the same ? :)