A React Native and Expo app on Supabase for a working cannabis retailer, running against a point-of-sale feed that refreshes the catalogue every fifteen minutes so what customers browse matches what is actually on the shelf. Category navigation, search, filters, stock indicators and medical labelling sit over curated product photography and brand marks. The most interesting constraint is a platform one: Google Play's cannabis policy does not permit native ordering, so iOS orders natively while Android hands off to the responsive web checkout — one product, two paths, because the rules differ per store. Payment and physical ID verification deliberately stay at the register, where they legally belong. Loyalty links to the POS so points accrue against finalised sales rather than app-side state.