There are some measured results available for certain older ios devices but I'm not able to find FOV numbers for newer models, specifically, iPhone 5s ~ 6s Plus and iPad 4 ~ iPad Pro. Also, the numbers listed on the above link don't match with some other calculated results.
I'm aware that FOV number can be read using the following API
NSLog(@"Camera's FOV is %f",myCamera.activeFormat.videoFieldOfView);
However, since I don't have all the models available at hand and the read numbers that are publicly available for some models also doesn't match measured/calculated results, I was wondering if there are reliable FOV numbers for most if not all iPhone/iPad models. Thanks.
I think you might want to take a look at
Table 4-5 iPhone 8 / iPhone 8 Plus / iPhone X Front Camera
Table 4-12 iPhone 7 / iPhone 7 Plus Front Camera
Table 4-15 iPhone 6s / iPhone 6s Plus Front Camera
Table 4-17 iPhone 6 / iPhone 6 Plus Front Camera
Table 4-19 iPhone SE Front Camera
Table 4-21 iPad Pro 12.9-inch (2nd generation) / iPad Pro 10.5-inch Front Camera
Table 4-23 iPad (5th generation) Front Camera
That's about all the calculations of FOVs out there. Also, they are from apple so I believe they are reliable.