Apple’s first foldable iPhone, the iPhone Duo , officially launched today, Friday October 23. Pre-order deliveries are arriving to customers, but supply is extremely tight – although anyone who didn’t order in advance may still be able to buy one in person, depending on local availability. That said, Apple has said it expects supply to sell out quickly. ‌iPhone Duo‌ pre-orders began October 16, with shipping estimates on Apple’s online store for newly-placed orders getting pushed back to January 25 within the first 30 minutes of pre-orders starting . That gives you some idea of just how popular the device is proving to be. Apple said earlier this week that Apple Stores will have limited ‌iPhone Duo‌ stock for walk-in customers today, in the U. S. , U. K. , Canada, Australia, Mexico, and several European countries…