If something is swoppable, it means it can be exchanged for something else.
Swoppable things are usually good because you can change them for something you like better.
Examples:
This toy is swoppable for a different one.
Are these stickers swoppable for candy?
The swoppable tickets can be traded for prizes.
I wish my vegetables were swoppable for ice cream!
In a magical world, everything is swoppable for anything else.
My old clothes are swoppable for new ones at the store.