I am not sure what you have to develop Mr Programmer,
but working with customer details it’s not easy, not easy to import not easy to update not easy to export not easy to do anything.
I installed SQL server to write a SQL query to read the customer detail and to do a small app to send SMS to customer throw my mobile for marketing purpose.
so, the app can read and update the customer details directly from the SQL databases so the sambapos customer details keep clean and up-to-date.
So, you can make an app but you can’t handle JSON??? All custom data store in 1 field in JSON format. You read the JSON data, parse it and extract what you need.
Ir doesn’t make sense to develop a solution based on your app site I imagine it is closed source and not free. Whereas SQL and JSON and standardised technologies which allow us to interact directly with the data, rather than having to use your property app.