Github Repo:
https://github.com/corsego/shoplify
Heroku Demo:
https://shoplify.herokuapp.com/​

allow_promotion_codes for checkout
https://github.com/corsego/shoplify/commit/a094810ff35e8a9f14843fe5dbad2ec93a6b6d50
product can have prices with different currencies
https://github.com/corsego/shoplify/commit/4870b0175c62df9c53ce155faafb909d51d6fcab
gem money-rails
https://github.com/corsego/shoplify/commit/ecce80910b73451691a1ff6f847172deec87807c

0:00 Stripe Coupons and Promocodes
3:32 Currencies
12:29 gem money-rails