Kodular - Much more than a modern app creator without coding
Xamarin.Android - Integrated environment for building not only native Android but iOS and Windows apps too.
Thunkable - Powerful but easy to use, drag-and-drop mobile app builder.
RAD Studio - RAD Studio 10.2 with Delphi Linux compiler is the fastest way to write, compile, package and deploy cross-platform native software applications. Learn more.
MIT App Inventor - App Inventor is a cloud-based tool, which means you can create apps for phones or tablets right in your web browser.
Rider - Rider is a cross-platform .NET IDE based on the IntelliJ platform and ReSharper.