Q :
I would like to delete a sound track from a portfolio in Foliobook.

But how do you? I can see no delete button or swipe gesture to do it.

 A : 

There is currently no way to delete a sound track.  We have made this change in our next update which we hope to have out in a couple of weeks. Until then it is necessary to use a workaround of which we know three

a) Delete the gallery and re-create it. Not ideal but may be suitable for some people.

b) Mute the sound using the speaker icon on the side controls. 

c) If in a presentation and sound is not required, use the audio mute switch on the side of the iPad to mute Foliobook's sound.