I know this is very subjective. My objective with this question is not to determine what is the best solution out there but collect some feedback and stories on what people been using. Threads like this are an opportunity to discover new stuff as well as I bet someone will link some niche kit that will make some other reader quite happy.
I am interested in learning what you enjoy using for cross-platform native GUI app development. The way I’m defining native here is anything that is not electron. I know that allows a lot of stuff in that would normally not be considered native such as languages that run on VMs and draw their own controls without using whatever the OS provides, but in my mind that is OK for this question. I’m specially curious about toolkits or languages that are nimble and allow you to get a lot done in terms of GUI without using too much resources.