Expo

What it is

Expo is an open source framework and set of tools for building apps with React Native. Its SDK gives JavaScript access to phone features such as the camera, file system, secure storage, SQLite and notifications, with modules that work the same way on iOS and Android. Apps are still real native apps, written in JavaScript or TypeScript with React components.

Around the SDK sits EAS, Expo's hosted service for building, signing and submitting apps, plus over-the-air updates. A team can produce store-ready iOS and Android builds without maintaining its own build machines for every step. EAS can also send builds straight to TestFlight and Google Play. The command-line tools let a developer start, run and test an app on a simulator or a real phone in minutes.

How I use it

• Rental Pilot's field app is built on Expo SDK 55 with React Native 0.83 and React 19, and is on the App Store.
• Builds go through Expo EAS; iOS releases go to TestFlight and the App Store with fastlane lanes.
• Offline-first: expo-sqlite queues deliveries, pickups and photo uploads on the phone and syncs when the network returns.
• Sign-in tokens live in the iOS Keychain through expo-secure-store.
• Camera capture with HEIC to JPEG conversion, an on-device signature pad on field tickets, PDFs viewed in the app, and a home-screen icon that can change per tenant.
• Chat messages and task assignments arrive through Expo push notifications.

Expo is the right tool when one small team needs a real native app on both platforms from one codebase, without spending its time on native build plumbing. I reach for it because Rental Pilot's field crews need an app that handles cameras, signatures and bad signal well, and Expo's modules cover most of that so I can spend my time on the work itself.

Questions