Yes, Android apps can and do have native libraries. Sometimes this can be part of a SDK, or otherwise out of the developers control.

Apps written in Flutter/Dart and React Native/Javascript both compile to native code with only shims to interface with the Java UI framework.

Flutter/Dart, yes, React Native/Javascript, no. With RN the app's code runs via an embedded JavaScript engine, and even when, say, Hermes is being used, it's still executing bytecode not native machine code.

Also important to note that any code that runs on Android's ART runtime (i.e. Kotlin and/or Java) can get some or all of its code AOT-compiled to machine code by the OS, either upon app install (if the app ships with baseline profiles) or in the background while the device is idle and charging.

Android apps can call into native code via JNI, which the platform supports.

Wonder if Android apps can also be fully native (C++)?

It is possible to have a project set up with a manifest which contains only a single activity with android.app.NativeActivity pointing to a .so, and zero lines of java/kotlin/flutter/whatever else - though your app initialization will go through usual hoops of spawning a java-based instance.

Minimal example would be https://github.com/android/ndk-samples/blob/master/native-ac..., though there are well established Qt based apps as well

I saw a project posted on here a while back about writing android apps with no java, only c.

There is no good reason to do it, but it is apparently possible.

https://github.com/cnlohr/rawdrawandroid

The Android Native Development Kit (NDK) allows building native code libraries for Android (typically C/C++, but this can include Rust). These can then be loaded and accessed by JNI on the Java/Kotlin side

* Brief overview of the NDK: https://developer.android.com/ndk/guides

* Guide to supporting 16KB page sizes with the NDK https://developer.android.com/guide/practices/page-sizes

Good to know, thank you!

Chrome browser on Android uses the same code base as Chrome on desktop including multi-process architecture. But it’s UI is in Java communicating with C++ using JNI.

I had no idea, thank you!