Hi, thanks for trying MasterPlan out - yeah, you're right that layering currently works by just raising whatever card is clicked last, andthere's no way to make sure it's a "background" card.
However, that is coincidentally the latest feature I implemented that I just have yet to release (partially because I've been very busy + getting sick over the past week), which should be exactly what you're looking for. Dragging cards onto a card will pin them, so clicking and moving the card underneath moves the cards on top until you intentionally move them off. I currently have it implemented for Map cards, but I'll extend it to images as well.
I'll see about putting the next update out this week.





