There are 3 types of apps:
1. Native apps
- iOS on Objective-C or Swift
- Android on Java
- Windows Phone on Net
2. Hybrid apps for all platforms altogether with Xamarin, React Native, Ionic, Angular Mobile Sencha Touch etc.
3. Web apps as responsive versions of website to work on any mobile device.
Read more at: https://thinkmobiles.com/blog/popular-types-of-apps/