What languages do I need to learn for mobile app development?

Flutter or react native

Flutter is golden

You are supposed to Google search this kind of question. You will find much better answers than you will get here.

Anyways, I believe Java and Kotlin are the most popular languages for developing Android apps; Swift is the preferred language for iOS apps.
Like I stated above, Google searching will give you better, more detailed answers. If you prefer videos, go on YouTube

This is a Guide I use for myself:

1. Need a Quick Job = React Native
2. Need Performance but with cross platform in mind = Flutter
3. Need Intense Performance and control over Hardware API or Gaming = Native
4. Need to convert website to mobile app = Cordova/PhoneGap
5. I am not leaving DotNet = Xamarin


Here is my No-BS list for picking platforms

hiehq:
What languages do I need to learn for mobile app development?

There are several ways to create mobile apps.
1) You can learn Java and Kotlin to create native Android apps, learn Swift to create iOS apps.

2) 2nd option will be to learn Flutter which requires you to learn the Dart Programming language. Any app created with flutter can run on both Android and iOS so you only need to learn one programming language and write the code once to run on both operating systems.

3) 3rd option is to learn React Native which works with JavaScript. Despite being similar to Flutter, I placed React Native as the 3rd option because it can actually make your app creation process faster than that of Flutter once you are vast in Web development. You will need a good knowledge of web development with HTML, CSS, JavaScript and React before you can comfortably use React Native. Now with React Native Webview feature, you can actually build a react website, pass the URL into React Native and you can get a Android app, iOS app and a Website all at once.

4) The 4th option is the least considered option which involves creating a Progressive Web App from an existing website. You can read more about Progressive Web App (PWA) online and I can assure you that you will be impressed by the technology.