Oh, you can do that in the app itself. I made these screenshots. If you view the stores there is a button that allows you to share that will automatically copy the json to the clipboard or you can click into the box and copy it. Pass that over and a friend can then copy it and paste it in if they also have the app. In these screenshots I used the default store in the app. You can create your own from the "stores" button, but it takes some time to add items in. If you make a cool merchant store share here in a post on the app's page and maybe some other people can use it :D
