Ability to undo last spread
No, as we can't predict every single time a user may leave or pause the the app. Think about desktop here as well.
If done fully client side, I would have to wait 1 swipe before sending data to the server. Meaning there would be that 1 swipe in limbo until either the user swiped again, or they closed the app.
Would be better if the server supported a function to undo a swipe on a card. May be only allow 1 endorsement change per post