Landing late at night in Shenzhen for my first trip to China, I was nervous about being able to navigate the city. I didn’t speak the language and had never been to Asia. Starting the next day I would have the services of a local translator, but for that first night, I was on my own.

Normally I use Google services for everything, but those are blocked in China. I opened my 桃園手機收購iphone, connected to an international Mifi, and tapped the Uber app. The interface alerted me that I would be switching to the Chinese version, controlled now by Uber’s rival-turned-business-partner Didi. The black screen turned a deep shade of red, and just like that, I hailed a cab.

I used Apple Maps to locate the apartment we had reserved through Airbnb. Then I found the same spot on the map in Uber, which automatically translated the location into Chinese. I showed that to the driver, and off we went.

When I arrived at the apartment building I was met by our hostess. She spoke only a few words of English (better than my Chinese), but not enough for us to really converse. Luckily we both had WeChat. The app opens up with a solitary figure standing on the moon, staring down at Earth from afar: a fitting image for a traveler in another world. My landlord would type something to me on WeChat and I would tap it, translating her characters to English. She did the same with my Western alphabet. A little notice popped up under the translation: “✓ Microsoft Translator.”

The next morning I woke up at the crack of dawn, my body exhausted but still on New York time. I used Apple Maps to locate a nearby Starbucks. I walked over, but the shop didn’t open for another half an hour. Luckily there was a McDonald’s next door, bustling with dozens of Chinese customers.

It occurred to me that retail franchises are in many ways like apps. They are built on a very specific code, so that anyone can easily plug and play. The merchant gets all the rules for opening up shop and servicing customers. The consumer knows exactly what buttons to press to get their order.

The kiosk inside the McDonald’s let me order in English, and the Ver桃園手機收購iphone terminal there accepted Apple Pay. Twelve hours into my trip I had navigated through the city, taken a taxi, ordered a meal, and not spoken a word to anyone. Later on I discovered a translation app from Baidu that felt like magic. I could scan text and have it translated, speak a sentence and get an audio file of it Chinese, or even take a picture of any object — a cup, key, or umbrella — and the app would use image recognition to understand what the object was and provide me with the corresponding Chinese word. It felt like we were just a few years from having a true Star Trek-style universal translator.

If I had been smart enough to register my WeChat account through Hong Kong, either by flying into that airport or using a VPN when creating my account, I could have loaded my bank account and credit card into the service. From there, an enormous array of possibilities open up for navigating the world by app.

WeChat, created by Tencent, seemed to be far and away the dominant service in Shenzhen. Every vendor, including supermarkets, restaurants, taxi cabs, and even small fruit stands on the street, accepted payment through WeChat. You opened up a QR code, the merchant scanned it with their phone, and money magically exchanged hands.

WeChat would also let me buy a railway or movie ticket, book a hotel room, pay a utility or phone bill, even make an appointment at a doctor, and many other little exchanges that in the past would have required me to struggle through a bilingual interaction or lean on a translator. With a working WeChat wallet, it seemed possible to navigate the entire country through a QR code.

But there’s a dark side to a single app that serves as the key to all things. When I went to purchase a local SIM card for my phone at China Telecom, it would only accept payment by WeChat, not card or cash. Our translator speculated that this was part of the government’s effort to carefully track the flow of information. They had recently eliminated the ability to buy prepaid burner-type packages, and customers can’t start an account with cash.

And while my smartphone unlocked some things for me, I missed out on dozens of interactions with actual people. It’s comforting to be in a cab ride home and whip out your phone to play a round of your favorite mobile game, but it comes at the expense of the memories you might make with your limited stay on the other side of the globe.

That’s the glass half-empty version. A more optimistic take is that eliminating the little struggles allows me to make more of my trip, to push further than I would if I was bogged-down on everyday transactions. I made plans one evening to meet up with a cousin who recently began working for a startup in Shenzhen. The Chinese SIM card I bought ended up malfunctioning in my Western smartphone, and so I had to fall back on my MiFi, WeChat, and Apple Maps to locate my cousin that night. Even with his fluent Chinese we had a hard time catching a cab during rush hour, so I called us an Uber instead.

The time I saved with my smartphone that night extended our adventure. He took me into Baishizou, a neighborhood separate from the modern city, controlled by a council of elders instead of the municipal government. It’s the last vestige of the rural fishing village that was Shenzhen 30 years ago, before it became megalopolis of 20 million people packed into high-rise towers.

Wandering down a dim back alley, we had to duck our heads under the low-hanging bundles of exposed power lines that snaked in and out of windows. Through an open door we saw a group of migrant laborers squatting around a poker game. A cloud of cigarette smoke drifted toward the ceiling, pooling above the bunk beds where men were sleeping three deep and six high.

We ate at MuWu, a restaurant founded by Barack Obama’s half brother, a Kenyan man who married a Taiwanese woman and started a chain of Chinese-style barbecue joints. As we settled in for a six-course meal, I checked in on Foursquare, creating a digital diary of my trip I’ll treasure. Because I had synced my Foursquare with Twitter and Facebook before I left, my Foursquare activity snuck past the Great Firewall, broadcasting my experience around the world.