Develop Mobile Commerce App

Develop a mobile commerce app Android native (Java + SQLite) and iOS native version. Also, develop a gate to the data. A web page where the partners insert the product correlated data into app database. All the codes must be commented to explain working schema for data and display construction. The app will also had to integrate with an already selected payment gateway to process and checkout orders. We need it to work just fine. The App must be NATIVE. We don't want to have web security issues, so the idea is to go just mobile. The primary action button (the rounded one on the right down corner) must be the buy button, and the products selected by one click. More details later on.