t’s simple, and official (registered as officially unlocked in Apple’s database)
it works with any iPhone, even on-contract (iPhone 2G, 3G, 3GS, 4, 4S, 5, 5s, iPhone 6, iPhone 6 Plus, iPhone 7, and iPhone 7 Plus)
it’s 100% guaranteed to unlock your iPhone
it works even if you are still under contract
the iPhone can’t be locked again, even if you update your device in iTunes
it does not void your iPhone warranty
no jailbreak or hacking required