Apple reported that "starting from June 1, 2016 all the apps that submitted to Apples Store must support IPv6-only networking. This is so because, Apple will be migrating IOS to IPv6. Therefore, starting with iOS 9, iOS will be migrating up IPv4 to IPv6.
Apple have decided that it’s high time to upgrade to the latest internet protocol.
To some Advanced developers, this is not going to be a problem. Apple stated that, "Most apps will not require any changes because IPv6 is already supported by NSURL Session and CFNetwork application programming interfaces (APIs)."
Therefore, if your app uses IPv4-specific APIs or hard-coded IP addresses, you are advised to change your program. Reading this is recommended Supporting IPv6 DNS64/NAT64 Networks and watching Your App and Next Generation Networks to get your heads up with IPv6.
Every developer has been has been following Apple. No one has seen the reason why they should be stressing and forcing developers to move to IPv6 where in the United States, however, 25.87 percent of Internet addresses are now using the IPv6 format.
According to Akamai, its latest Internet report, explained, "once again, cable and wireless/mobile providers continued to drive the largest volumes of IPv6 requests, as many are leading the way for IPv6 adoption in their respective countries. In the fourth quarter, Verizon Wireless and Belgium's Telenet once again led the pack as the only two network providers with more than half of their requests to Akamai made over IPv6."
Adopting IPv6, and dropping IPv4 for Android and IOS can be considered a welcomed growth because it will enhance the quality and the speed of interned services delivered by mobile network providers. Although this will actually stress some developers, it will help them to deliver a good customer experience to its users. Hence adopting IPv6, and dropping IPv4 for android and IOS is a welcomed development