Please make sure that the volume of your iOS device is turned up.
Around 2/3rds is the recommended amount.
If you still do not hear anything, make sure that there is not a problem with your headphones or speakers.
If you have a case or cover on your iOS device it may prevent the Mogees connector from being inserted all the way. Remove the case or cover and try connect your Mogees again.
Try opening another music application (like Apple Music or Spotify) and playing a song even with your Mogees connected. You should be able to hear the music playing.
You cannot use Bluetooth speakers with Mogees.
If none of the above work, please complete the Mogees hardware test.