Popup after Added To cart with Discount Offer and Timer

[Conversionss]

Hi!

Is there an app that does the following:

When a customer adds an item to cart I'd like them to receive a popup with a timer.

The popup displays a X% discount on the entire store if the customer checks out within Y minutes. 

For example: 20% on the entire store if they check out within 30 minutes

I've browsed through countless apps, but not found what I'm looking for. Any help or advice is highly appreciated!