Kodular - Much more than a modern app creator without coding
Bizness Apps - Create your own app or become a reseller and build apps for others
Xamarin.Android - Integrated environment for building not only native Android but iOS and Windows apps too.
Siberian CMS - Siberian is an Open-Source and Free App Maker. Unlimited Push Notifications. Unlimited features. Fully Customizable. Download it and build your own app now!
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.
Dropsource - Mobile development platform for building native iOS & Android apps