[Serendipia]

When I open a song I wished there would be shown the first annotation layer and i could flip through the others in any way. 
I tried to use the touch settings for the left and right upper corner and set them on "previous and next annotation layer". But nothing at all happens when I tap the upper corners.
What would be the best approach to be able to flip through tha annotation layers? 
Thanks for any help, Marion