Thunkable - Powerful but easy to use, drag-and-drop mobile app builder.
Bubble.io - Building tech is slow and expensive. Bubble is the most powerful no-code platform for creating digital products.
Xamarin.Android - Integrated environment for building not only native Android but iOS and Windows apps too.
FlutterFlow - FlutterFlow is an online low-code platform that empowers people to build native mobile apps visually.
Kodular - Much more than a modern app creator without coding
Appsbar - Appsbar is a free mobile app builder.