"I want to see my app running on a real iPhone, but the Apple Developer Program costs $99 a year just to get started..."
Rork Companion solves this problem. With this free app, you can test any app you build in Rork on a real iPhone without signing up for Apple Developer, installing Xcode, or paying anything. Scan a QR code, and your app appears on your phone. That's the entire process.
What Is Rork Companion?
Rork Companion is a dedicated app for previewing Rork-built apps on physical iOS devices in real time. It's free on the App Store, and all you need to use it is a Rork account (also free).
Normally, testing an iOS app on a real device requires either TestFlight (for beta distribution) or a direct install via Xcode — both of which require enrollment in Apple's Developer Program at $99/year.
Rork Companion removes that requirement entirely, making the first step of app development genuinely free. Under the hood, Rork's servers stream the JavaScript bundle you're editing, and Companion renders it on the device. It's a different mechanism from TestFlight, which bakes a native binary — think of Companion as purpose-built for "show me what I'm editing, right now."
How to Get Started with Real-Device Testing
The setup takes just a few minutes.
Start by downloading the Rork Companion app from the App Store on your iPhone. Search for "Rork Companion" — it's free.
Then, open rork.app in your browser and either create a new app or open an existing one. Look for the QR code icon in the top-right corner of the editor or in the preview area.
Finally, open Rork Companion on your iPhone, tap to scan, and point the camera at that QR code. Rork Companion downloads and launches your app directly on your phone.
That's it. Unlike the browser simulator, this runs in a real iOS environment on actual hardware. One prerequisite worth keeping in mind: make sure the account you're logged into in the browser matches the one you're signed into in Companion. If they differ, the scan can succeed but the project won't be found.
When It Won't Connect or Update
A fair number of people stumble on the first scan, so here's a quick triage list, ordered by how often each issue comes up.
| Symptom | What to check first |
|---|---|
| The QR code won't scan at all | Camera permission, screen brightness, and whether the preview is actually running on the Rork side |
| The scan works but the app never appears | Whether the browser and Companion use the same account, and whether office Wi-Fi / VPN / firewall is blocking the connection |
| Code changes don't show up on the device | Whether Rork reloaded the change; close the app in Companion and re-scan the QR code |
| Loading freezes partway | Large image or video assets still transferring; switch networks and retry |
In my experience, the most common culprit is the second one — the network. Something that connects on the first try at home can get blocked on guest Wi-Fi or a tethered connection. When it won't work, switch your iPhone to its cellular connection and try again; that quickly tells you whether the problem is on the network side.
What to Check During Real-Device Testing
Real-device testing surfaces things that a browser simulator simply can't show you. Here are the key areas to focus on.
Touch interactions feel different on a physical screen. Check that buttons are easy to tap, that swipe gestures behave as expected, and that nothing requires precision that a real finger can't deliver. Apple's Human Interface Guidelines recommend a minimum tap target size of 44×44 points for good reason.
Safe areas and the Dynamic Island are easy to misjudge without a real device. Confirm that a title or status element at the top of the screen doesn't collide with the clock or Dynamic Island, and that a bottom button doesn't crowd the home indicator. Even with SafeAreaView in place, a fixed header or background color can break the spacing.
Performance is another area where the real device tells the truth. Watch for hesitation during screen transitions, jank while scrolling, or lag when the keyboard appears. The difference between simulated and actual hardware performance can be significant.
Layout across screen sizes is worth checking if you can. iPhone screen sizes vary considerably. Make sure text isn't cut off on smaller models and that the layout doesn't look sparse on larger ones.
Dark mode is easy to miss in early testing. Toggle your iPhone to dark mode in Settings and verify that text remains readable, backgrounds contrast properly, and no elements disappear or look broken.
What Companion Can't Test (the dividing line)
As handy as it is, Rork Companion is a preview that "shows your current code" — it is not the production native app itself. The following areas either can't be verified accurately in Companion, or behave differently from a real build.
- Real push-notification behavior — permission dialogs and background delivery need a built artifact to verify correctly.
- In-app purchases (StoreKit) — sandbox purchase testing requires TestFlight distribution.
- Certain native modules — native dependencies not bundled into Companion may error on load.
- Background behavior and launch speed — actual cold-start and memory behavior should be measured on a production build.
In short, Companion is a tool for iterating quickly on UI and feel. Once you reach final verification of notifications, purchases, or performance, switch to TestFlight via EAS Build, or Rork Max's cloud build. Drawing that line up front saves you from confusion later.
What Only a Real Device Could Show Me
Across the wallpaper apps I've shipped, one lesson kept repeating itself: something can look flawless in a browser simulator and still fall apart the moment it lands on actual hardware.
Screen-size differences gave me the most trouble. iPhones range from the 4-inch SE to the 6.9-inch Pro Max, and when you serve different image assets per resolution, a thumbnail grid whose margins looked perfectly balanced on my Mac would — the instant I pushed it to a small iPhone SE in my hand — clip the bottom row of cells in half. It was only on the real device that I could see, plainly, "this isn't ready to ship yet."
The other thing a simulator never reproduced for me was the feel of scrolling. A screen packed with images makes the slightest stutter during a fast flick feel cheap — and you cannot catch that with a mouse wheel. You have to hold the device, scroll with your own thumb, and feel that "I want this just a touch smoother" before you can fix it. That hold-it-in-your-hand step is exactly what Rork Companion lets you reach before you ever pay for Apple Developer.
How Rork Companion Relates to Rork Max
Rork Companion works with standard Rork projects built on React Native and Expo. If you're using Rork Max — which generates native SwiftUI apps — you can still use Companion for early UI review, but the final pre-submission testing for Rork Max projects typically uses the full cloud Mac build and the 2-click App Store publishing workflow.
A practical way to think about it: use Rork Companion for fast idea validation and early UI testing, and use Rork Max's full pipeline for the final App Store submission build.
Common Questions
Can I use Rork Companion on Android? Rork Companion is currently iOS only. For Android testing, Rork's browser preview covers most cases, or you can use Expo Go.
Does the app update automatically when I make changes in Rork? In some cases, saving changes in Rork will update what's shown in Rork Companion. For the most reliable fresh view, re-scanning the QR code is the safest approach.
Do I eventually need Apple Developer if I want to publish? Yes. App Store distribution requires Apple Developer enrollment. Rork Companion is specifically for the development and testing phase — it doesn't publish apps.
Wrapping Up
Rork Companion lowers the barrier to getting started with iOS development in a meaningful way. Trying out an idea on a real device — before committing to any paid program — gives you honest feedback faster and with less friction.
The key is to settle the role split early: lock down UI and feel in Companion, and leave the final checks for notifications, purchases, and performance to a production build. Keep that in mind and the later stages go much more smoothly.
If you haven't started with Rork yet, head to rork.app and give it a try for free.