I was just curious whether apple use TLC or MLC for iPhone 6S. Based on 16GB NAND part number from ifixit and chip works, they were all MLC from Toshiba or Hynix. I compiled https://github.com/matthiasgasser/IOKitBrowser in Xcode and ran it on my iPhone 6S+ 64GB. Based on output my 64GB NAND is TLC. Interestingly it seems that apple developed embed NVMe SSD controller and put it into A9 SOC. Lastly, it seems that the code name of A9 is "twister".