What's the best undo button position for a tinder X ecommerce app

Question

I'm working on an ecommerce app that uses a tinder like approach to browse products.

http://fashionista.com/2014/05/tinder-for-fashion-apps

the core ui will be right to add like and left to not like with swiping functionality as well.

some of these apps have the undo button and i'm trying to figure on where is the best position to put it. tinder seems to put a smaller undo button slightly above to the left of the reject button. is this an optimal place or is there a better position in an ecommerce context.

Answer 1

Alright, so since this is a shopping app, I assume there is no arm in jumping to previous items at will?

If so, I have the feeling a persitant "history" would work best. This is a little proposition, might be way above your scope. Let me know!