Speaking of Dear ImGui, I recently wrote a super minimal Profiler/Flamegraph for it. The model and profiling logic is ~60 LOC with the UI adding another ~50 LOC. It's written in Odin but is so simple, it should be trivial to port to other languages and UI systems.
https://alek-tron.com/FlameGraph/flamegraph.html

Nothing big but I wrote a custom Windows/DirectX backend for Dear ImGui.
On one hand to just have a native Odin backend. But also to serve as an easy introduction to others who would like to integrate imgui into their own renderers/OS layers, like I used to do. It doesn't cover all edge cases and features like the official backends, but that let me keep things simple.
https://github.com/alektron/imgui-odin-backends