https://ugetdm.com/ This is the app's website.The app's interface looks 100% like a linux application.It is a linux application converted to a Windows one?The app was mainly developed for linux Or it is just a windows application with Linux interface?If it is a linux app, how they converted it to a windows one?
uGet is written using a multi-platform toolkit called GTK. GTK determines how the application looks. It is widely used among Linux applications and I guess that's where your confusion comes from. There are a lot of applications on Windows using GTK but the native solution is used more often.