I don't have anything like that but I do have these instructions I'd made for a friend on the variables in the json export.
This explains the json store that is in the export from the app.
title == the name of the custom store
count == the number of items in the store
id == needs to be "-"
store_items == is the list of items. There are two items in the example below.
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store_items explained
t = name of the item
l = the description text of the item (that is a lower case L not and i)
n = the quantity that the item is sold in. Example, arrows are sold in batches of 20.
v = value of the item. How much it costs.
w = the weight of the item.
i = the item's icon name. There are a lot of these now, but if it is an invalid string it will just display as a white square.
{"title":"Test Store","count":2,"id":"-","store_items":[{"t":"a thing","l":"a thingy - an item of some importance. Why else would you have put it in your bag?","n":1,"v":1,"w":1.0,"i":"Battle_axe"},{"t":"A Hammer","l":"lore text","n":1,"v":99875,"w":1.0,"i":"SilverHammer"}]}