It would be really useful to be able to slow down an mp3 while keeping the pitch the same. This would be a great aid in learning a new song or working through a difficult passage. There could be a slider control on the mp3 player dialog screen for example.
This has been asked for many times in the past, and my response was that it was going to be very difficult to add as I was going to have write a lot of the code myself. Luckily, I recently found a library that makes this much easier and it's now available for both Android and Windows 10, so I'll be adding the ability to change playback speed as well as pitch shift. I should also be able to add things like crossfading between tracks. I just need to finish a couple of other big updates before I can tackle this.
Mike