No matter the year, Google has proved itself to be the leader. In 2017, Google created the open-source framework, Flutter for mobile app development. This framework is so great that even in 2023, it's still preferred by mobile web developers. In fact, it's the second most popular mobile framework till date.

It uses Dart to create user-friendly and interactive apps. The upside of using Flutter is that developers can utilize Dart's features as well. For instance, Dart has sound null safety that identifies common bugs. Developers using Flutter can also avail this feature - this can save a lot of their time. Apart from this, some other popular features of Flutter are:

1. Developers can make cross-platform apps without writing more code in Flutter. With one codebase, they can create apps for multiple platforms.

2. There's a hot reload function in Flutter that will let developers see updates without pressing the 'restart' option.

3. Flutter has both ready-made and customizable widgets. This means developers don't need to create widgets from scratch anymore.

4. Since Flutter doesn't use bridges like JavaScript and WebView to communicate between the app and platform, Flutter-made apps are fast and face fewer performance problems.

What's even better? If you want to change contrast, font size, etc., in Flutter, you can share both the UI code and the UI itself.

In most cross-platforms, code sharing is possible only between target platforms. Also, since Flutter apps are created with machine code, developers don't encounter performance bugs.

And no, in Flutter, developers don't need to test the app separately on different platforms. They just need to perform one comprehensive app test. But let's face it - despite all these features, Flutter does lack a lot. For instance, native APIs can't be called directly from Dart. Although vector animations and graphics are supported by Flutter, sometimes problems do occur. But, I'm certain that these problems will be solved over the years in the Flutter release. Because after all Flutter is Google's brainchild.