MultiSim - One build. Every simulator.
Xcode forces you to test one simulator at a time. Switch simulator, rebuild, run. Repeat for every screen size. Minutes wasted, focus broken.
MultiSim ends this loop.
Press Ctrl+Shift+R. Your app installs and launches on every open simulator at once. iPhone SE to iPad Pro, all updated in one shot.
Focus stays in your editor. Logs persist across builds. Menu bar app. Zero telemetry.
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Hey Product Hunt. I'm the developer behind MultiSim. I've been building this tool for a long time, and now I'm making it available to everyone.
If you're developing for iOS, especially with UIKit, you know this problem. You want to see how every change behaves across multiple simulators, screen sizes, iOS versions, and user scenarios. You compile for iPhone 8, small screen, old operating system. Then iPhone 13 mini. Then iPhone Air. Then iPhone 17 Pro Max. Each time you pick a simulator from the dropdown in Xcode, hit Build, and wait. Does it behave differently on iOS 15, iOS 18, or the just-released iOS 26.4? What does a user who hasn't completed onboarding, who isn't premium, actually see? What about iPad? What about the Watch bundle? You check each one, one by one, same steps every time.
Then there's the focus problem. It keeps jumping to the simulator. You took a build, the simulator launched, you want to keep typing but now your keyboard is going to the simulator. You grab the mouse, click back into Xcode, try to pick up where you left off. You noticed something odd, quickly hit Command+R, but focus was on the simulator, and a screen recording started. If you're working on multiple monitors, that tiny indicator is easy to miss. An hour later, there's a useless recording file on your desktop.
Every time you switch to a new simulator, the previous logs are gone too. Remembering what you saw is entirely up to you. Wouldn't it be incredible to see all of them at once?
MultiSim eliminates all of these problems. Whether you have one simulator or dozens open, the moment you hit Build and Run, they all compile and launch at the same time. Focus never leaves Xcode. No more accidentally hitting Command+R in the wrong window.
It also detects which simulator you're on and shows you its output. Just click the simulator you want to inspect. You can customize the log screen and filter out lines you don't need. New entries get highlighted with a flash, and if there's a URL in the output, you can click it to open directly in your browser. Zoom, font, theme: all visual settings are fully in your hands.
You don't even need to switch to Xcode. Whether you're in Terminal, VS Code, or Cursor, you can trigger a build instantly with your custom shortcut. Xcode runs in the background, simulators update, and you never get interrupted.
We have a feature list we're working on. We'd love your input too. What would be useful for you?
MultiSim is on the Mac App Store right now. Free. If you have questions, I'm right here.