The UI looks very good, it's simple to use with intuitive features which makes things easier for me as I'm not tech savvy at all! It does what you need without being overwhelming or too easy-to-use (it has both).
There isn't much else; everything works well but nothing really stands out in particular other than how clean/simple they are overall - perhaps more options would be nice? We're taking screenshots from websites so this helps us make sure we don’t miss anything important when reviewing them later down line if needed by our team.