Qt - Powerful, flexible and easy to use, Qt will help you not only meet your tight deadline, but also reduce the maintainable code by an astonishing percentage.
WompMobile - WompMobile offers tow kind of functions – first creating new mobile apps and secondly converting the websites into mobile applications.
JUCE - JUCE is a wide-ranging C++ class library for building rich cross-platform applications and plugins...
AppGyver Composer - Visual enterprise-grade low code mobile app builder
NoesisGUI - User Interface library for games and real-time applications.
Mendix - Mendix is the fastest and easiest low-code platform used by businesses to create and continuously improve mobile and web apps at scale.