EDIT: Issue has been fixed, but leaving workaround here just in case.
For everyone experiencing the same issue with the white screen when the PATS/GPS apps are first introduced, try hitting on Back to return to the conversation with Zorro and open the phone menu (right click on PC/click Phone on Android). You'll see that both apps are already there, so open the GPS app and close the phone menu while it's still open (right click on PC/X under the phone screen on Android).
This should let you use it once the conversation ends and allow you to get out of the house. Once outside, you can freely use any app that you want and continue to explore the current content, but take into account that if you go back to the house manually, use PATS inside, or go to sleep/bathroom, the white screen issue will continue (events such as the getting tired out or washing the bathroom for Boss will not trigger this issue even if they take you inside the house).
Also, after you meet 5 different people, the next part of the story triggers and at the end of it the error will happen again with no way of fixing it since you can't open the phone during conversations anymore, so try having a couple of saves on hand until it gets fixed.