This is how we created Japan Direct, from the idea to the App Store in almost no time. We studied at the university together and used to spend quick some time reverse engineered apps and websites, but he found in no time the best way to get those data without knowing their data model or API. My friend focused on the user journey within the app, we redefined what was the Minimum Viable Product of our project and cut couple features we had (like advance research, sorting result etc).