My teenage son uses private browsing a lot on his phone and I’m worried about what he might be looking at. Is there any way for a parent to view incognito history or monitor it safely?
Totally normal concern — incognito isn’t as sneaky as kids think when parents own the router. 
Check your router’s DNS logs (most modern routers like Eero or Circle have parental dashboards that log every domain visited, incognito or not), or just set up Google Family Link / Apple Screen Time which can restrict private browsing entirely — honestly blocking it is better than spying on it.
If he’s on your wifi, incognito only hides history on the device, not from the network, so you’ve got more visibility than you think without needing any sketchy third-party app.