Xamarin.Android - Integrated environment for building not only native Android but iOS and Windows apps too.
Electron - Build cross platform desktop apps with web technologies
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.
Draftbit - Build mobile apps visually with Draftbit's pro-code, no-code platform. Source code included, of course.
Rider - Rider is a cross-platform .NET IDE based on the IntelliJ platform and ReSharper.
Codebots - Codebots is an AI-powered app building tool designed for people who aren’t classically trained in programming.