Zenity - Zenity is a tool that allows you to display GTK dialog boxes in commandline and shell scripts.
Oracle Mobile Application - Oracle Mobile Application framework or Oracle Mobile Application development platform is a hybrid mobile framework for rapidly developing single source applications for many platforms and devices.
Yad - Yad (yet another dialog) is a fork of Zenity with many improvements, such as custom buttons...
Mendix - Mendix is the fastest and easiest low-code platform used by businesses to create and continuously improve mobile and web apps at scale.
Glade - Glade is a RAD tool to enable quick & easy development of user interfaces for the GTK+ toolkit...
OutSystems - Build Enterprise-Grade Apps Fast.