Android: If you're fond of listening to podcasts or audiobooks at faster than normal speed to get through them quicker, XSpeedPlayer can help. The app will play back audio files on your phone at a speed you set.
XSpeedPlayer allows you to set the playback speed of your audio files faster or slower by as much as to 400% and as little as 25%. The app supports MP3 and WAV files, and when it changes the audio playback speed, it does so without changing the pitch, so you avoid turning all of your podcast hosts into chipmunks inadvertently.
The app works well if you're playing audio back in order to listen to it faster, but it also works if you're trying to take your time and listen to your audiobooks over a longer period of time. XSpeedPlayer is completely free and available now in the Android App Store.