The Pongo app is used to control a Pongo music player connected to your local network and your stereo. The Connect screen locates the Pongo players on your network. After a Pongo player is selected the app opens the Player screen which displays the players html-based controller web app to select songs to be played.
Since the song selection screen includes album art, which can not be displayed on the App Store, the store screenshots show only the initial connection screen and the player screen while a song is being played.