In an earlier post, I outlined the brick & mortar retailers that will accept Apple Pay beginning on October 20. The list is far smaller and completely different for apps:

airbnb, Apple, Cherish, Disney Store, Fancy, Groupon, Hotel Tonight, Houzz, Instacart, lyft, MLB.com, OpenTable, Panera, Spring, Staples, Target, Tickets.com, Uber.

Interestingly, the only retailer that will accept in-store and through app is Apple.