SquareLine Studio
 

Design and build
UIs with ease
Next-generation UI editor for individuals and professionals to design and develop beautiful UIs for your embedded devices quickly and easily.
All in one:
Design, prototype, and develop in the same software.
Vendor agnostic
Exports platform independent C or MicroPython code for LVGL which can be compiled for any vendor's device.
Iterate without re-building
Just click the Play button to try out the UI instantly without rebuilding it in a pixel perfect preview.
Components
Create custom components from the built in widgets using styles, animations and events.

https://squareline.io/