Powerful and easy-to-use embedded GUI library with many widgets, advanced visual effects (opacity, antialiasing, animations) and low memory requirements (16K RAM, 64K Flash).
I haven't tried LVGL, but it looks interesting: https://lvgl.io
NOTE: The number of mentions on this list indicates mentions on common posts plus user suggested alternatives. Hence, a higher number means a more popular project.
1 project | reddit.com/r/embeddedlinux | 15 Nov 2021
LVGL – Light and Versatile Embedded Graphics Library
1 project | news.ycombinator.com | 5 Nov 2021
LVGL - Light and Versatile Embedded Graphics Library (micropython)
1 project | reddit.com/r/Python | 16 Oct 2021
What GUI library for medical devices ?
1 project | reddit.com/r/C_Programming | 30 Aug 2021
Looking for a place to start learning about designing multipage UI for an st7789 TFT LCD display?
1 project | reddit.com/r/esp32 | 16 Apr 2021