Install kuiviewer by entering the following commands in the terminal:
sudo apt update sudo apt install kuiviewer
Description:
viewer for Qt Designer user interface files
KUIViewer is a utility to display and check user interface (.ui) files created in Qt Designer. The interfaces can be shown in a variety of different widget styles to ensure that they display correctly in any environment. . The Qt Designer itself is in the package qt4-designer. . This package is part of the KDE Software Development Kit module.
Homepage: http://www.kde.org/
Version: 4:17.12.3-0ubuntu1
Section: universe/devel