What do I need to know to make an app?

Question

Hi, I want to create an app on both android and ios. The app should let users add information for each country about bike touring. I want to learn the required languages to make this app. I know html, css and I'm learning the basics of Java. I know that android uses Kotlin and ios uses swift. But which other languages should I know?

Some more info about the app I want to create. Users will first see a list of all countries. When they click for example "Peru", they land on the page of Peru. The page contains info about visas, border crossings, cycle routes, safety, blogs, videos and more. The user should be able to add information to each chapter themselves, and it should become visible to all other users. The data thus needs to be stored. Also, each chapter has its own form of which information is required. For example, the form for the chapter border crossing should contain the opportunity to create blocks of other countries such as colombia, chile, bolivia, etc. Each block should contain editable text.

Answer 1

React native maybe an option for you if you don't want to use Kotlin or Swift.