While 51.2 million sold iPhones in fiscal 2016 (ending March 31) is nothing to scuff at it is a far cry from fiscal 2015's 61 million sold (16 percent year-on-year decline). Analyst seem to suggest it's partly to do with reaching mature levels in previously not fully tapped smartphone markets like China. The new, cheaper iPhone SE went on sale on March 31 and is not included in these numbers and it could of course have a positive effect on sales. But Apple has a lot riding on iPhone 7, that's for sure.
If this decline is permanent it and set to continue it could have a major impact on mobile gaming, as while Android is the larger platform in terms of users, gaming companies tend to make the most revenue on the Apple platform. It's way too soon for any drastic conclusions to be drawn, but nevertheless this is something of an historical shift as for the first time ever fewer iPhones were sold in the last twelve months compared to the twelve months preceeding that.
Elsewhere at Apple both iPad and Mac sales are down, while services (includes iTunes, App Apple Music, etc) is up 20%. It's not possible to discern from Apple's numbers whether individual products like Apple Watch or Apple TVs are doing well, but given that the Apple eco-system has reached one billion units it's no surprises that services are bringing in record numbers.
Thanks, TechCrunch.