I want to make a cross-platform desktop app which has a small config file on local filesystem.
Where is the best path to store application data on each OS?

>Solution :

Usually games or apps whose data is to be stored,and not deleted even after uninstalling the app itself,is stored in the users own path:

C:/Users/username/appdata

The appdata directory is hidden so you can either go there from cmd,or unhide it from:

folder options(search in windows tab)/view

Hope this was useful.