Annoying, Design lacking for cart

Ive finally had it with Groupon and this app as well! You can only "Buy" each item you look at... no ability to "add to cart" and continue shopping. So if you want to go back and add more items - say for a coupon code - you cant because the cart wont save it. Wth?!

shandawn about Groupon - Local Deals Near Me, v17.10