Sync Data from shopify Like photos, description, price ,stock to MYSQL or FIREBASE
Then create independent App in FLUTTER which will not have Payment gateway but after adding products they will click to finalize order with OTP on CREDIT. ITS sort of buy now pay later.
Data syncing should be accurate may be through cron.
Flutter design should be decent
Other features , app will have basic Admin in php or laravel to do the following
--Create/disable users ourselves as registration will not be open
--custom price setting for custom users (will have formula based on price fetched from shopify)
-- Dashboard with orders report, facility to mark fulfilled orders, auto email system(diff events)
--adding data for parcel status manually.
--Cancel orders and reports,
--pusing notification to app
--Fetch data and accommodate in design (data we sync in mysql or firebase)
--buy on credit
--create lists for quick buying
-cart system will be there but no payment system
--good detailed product searching system
--Publish both apps on App store and play store respectively