Xcode 8: how to change targeted device family

Question

I developed an app for iOS 9/10 for iphone devices but my client would like to present and show it first running on an iPAD (always iOS 9/10). I have tried to compile and run it on my iPAD mini but the result is awful. I mean that the visible screen is much smaller than the one of the iPAD and moreover it is very slow and the graphics is busted. This is strange because I wrote many constraints and my app shows good on every kind of iphone (> 4S). Moreover the app completely crashes when I tap on a table cell row to show the second View Controller... Why do I see this on ipad? Shall I change the device target which at the beginning was set to iphone only? In Xcode 8, under project --> Build Settings --> Targeted Device Family I see 3 options: 1, 2 and 1,2. What do they mean?

Solution

iPhone/iPod touch is 1, iPad is 2, and universal (iPhone and iPad) is 1,2.