LVGL is an open-source graphics library to create embedded GUI. By its flexibility, this toolkit is well matching Oniro project's requirements to build a multiple kernel OS for IoT devices or enable interactions in a multiple devices environment. UI toolkits are well established in CPU world (desktop, mobile), but what about in more constrained system ? Often tied to one vendor, the choice is often limited. However OpenSource project LVGL provides everything developers need to create embedded GUI with easy-to-use graphical elements, beautiful visual effects and low memory footprint. This library is compact and flexible enough to be thread through a regular Linux system. Of course this will not compete with other popular frameworks like Qt or GTK, but it has some advantages worth sharing: where portability matters more than eye candy features. Oniro's Bitbake recipes enable makers to build products with user interface in a Yocto environment that can target different kernels or graphics systems. Oniro's blueprints will illustrate integration details to match a product requirement. Demos of vending machine (running on Linux+Wayland) or keypad (on Zephyr MCU OS) will be shown too.