Check below use case for Login screen,
Now for field title and subtitles font family should be “Roboto” (just example). And font size should be "10" and Font color should be “#DCDCDC” for example.
Now how do I verify it mobile app is satisfying above requirements or not? It can be done manually but it's time consuming and chance of human error. So pls suggest any tool or app that will identify the font style of any mobile app developed either in Native or Hybrid.