I've been building a GUI with Makie for a personal project and its pretty powerful. It removes virtually all boilerplate code, and lets you add widgets easily.

I've been building a GUI with Makie for a personal project and its pretty powerful. It removes virtually all boilerplate code, and lets you add widgets easily. It uses Observables to allow for automatic updates to data values, which can make life much easier. You just need to draw a graph once and you can update the Observable whenever you want - the graph will redraw the data instantly. The only drawbacks I would say are the docs needing to be expanded more and more widgets to be included (such as a menu bar).