Love it

Must admit, it took me awhile to learn the features of this app. The learning curve is lengthier than most. But I now love it to death. Previous reviewer complained about the undo not working as expected. It could be that the mask was still on. Once you mask an item, and make/save changes to the masked area, the mask is still on. If you want to make any more edits to the layer, you have to deselect the mask . Took me awhile to figure that out.

Summatra about Leonardo - Photo Layer Editor