Thirsty for an ice-cold, fresh-squeezed lemonade on a hot summer Saturday in Istanbul, I open up the KapGel app. Lo and behold, free fresh lemonade in the specials! Although both the lemonade and the delivery for specials are free, the app requires a credit card for registration. The app crashes when I enter my debit card on an iPhone 4. I realize that I need to register a credit card with the app on an iPhone 8 to take advantage of the specials. Desperate for juice, I message a friend at KapGel to order on my behalf. My lemonade is going to be late, he says, orders are exploding! I can deliver today, I offer. So begins my day as a KapGel hero courier! I speed walk up Istiklal Avenue, squeezing past the throngs of locals and tourists, and cross Taksim Square, which continues to look harsh and ugly despite the grey brick makeover underway. I catch a bus and ride a couple stops. The office entrance does not line up with a crosswalk so I jayw...