Ionic Framework - A front-end SDK to develop applications with HTML5 , CSS3 and JavaScript.
JavaScript - Lightweight, interpreted, object-oriented language with first-class functions
MobileUI - A cross-platform framework for developing mobile apps (iOS, Android) with native UI in Java and Kotlin.
Allegro - Allegro 4 and Allegro 5 are cross-platform, libraries mainly aimed at video game and multimedia...
React Native - A framework for building native apps with React
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.