I looked at the fonts because I was seeing a difference between my sketch-file and the app. To approach the app's original design, we need these tree font-weights of Montserrat-font (instead of the 400,800 it is now):

• extralight (200)
• light (300)
• bold (700)

Importing these weights automatically solves the difference and shows the fonts as intended.
@import url('https://fonts.googleapis.com/css?family=Montserrat:200,300,700');