Have you ever had an annoying friend who always asks you the time of the day because he's too lazy to pick up his shiny and cutting edge smartphone?
In this case this app suits your needs by displaying the current time via a QR Code, forcing your friend to pick his phone out of his pocket to actually SEE what time is it.
tl;dr: This app is a clock but it shows a QR code containing the time rather than the actual time.
Note: free version, fully functional but ad supported. A paid version without ads is also available.