Why We Built SimToolbox

You're debugging something — maybe a file that's missing, maybe a database with unexpected rows, maybe a setting that didn't save — and you need to look at what's actually inside your app's simulator. So you do what we've all done a hundred times:

xcrun simctl get_app_container booted com.yourcompany.yourapp data

Copy the path. Open Finder. Paste. Navigate through three levels of opaque UUIDs. Find the Documents folder. Realise you actually needed Library/Caches. Go back. Click through again. Then the simulator resets, and the whole path changes.

It's not dramatic. It's just friction — a tiny tax you pay dozens of times a week. And it's not just the file paths:

• "What's in my app's Info.plist again?"
• "How much disk space is this app actually using?"
• "Did that migration actually write the new rows to SQLite?"
• "Which simulator has the build I was testing yesterday?"

Each one is solvable with terminal commands and Finder. None of them are hard. But they all pull you out of your flow. At some point last year, we got frustrated enough to do something about it.

What SimToolbox Does

SimToolbox lives in your menu bar and gives you instant access to every iOS Simulator on your machine. Here's what's inside.

View All Simulators

All your iOS, iPadOS, watchOS, tvOS, and visionOS simulators, grouped by runtime — one click away. You can filter to only show devices with apps installed, which cuts through the noise immediately. No more guessing which device has your build.

Browse Simulator Folders

Jump straight to any app's Bundle, Documents, Caches, or Library directory without needing to remember paths or navigate through layers of UUIDs in Finder. Select an app, pick a folder, and you're there.

Inspect Simulators

Simulator Inspector gives you a sortable overview of every simulator on your machine — with columns for app count, app size, and total disk usage. Useful for figuring out which simulators are eating your disk space, or just tracking down a specific build.

Bundle Inspector lets you inspect any app's Info.plist with a structured summary, extracted entitlements, and a raw plist browser. Everything you'd normally dig out with plutil or Finder, surfaced in one view.

Storage Inspector provides a visual disk usage breakdown for any app's data directory. Colour-coded bars show where the space is going, and an expandable folder tree lets you drill into the details.

Watch Simulators

Database Watcher monitors your app's SQLite databases in real time — discovers them automatically, detects row-level changes, and shows you the generated SQL. When you're debugging migrations or persistence logic, being able to see exactly what's happening to your database as it happens is genuinely better than querying it after the fact.

Filesystem Watcher streams file additions, modifications, and deletions as they happen. Coloured status icons make it easy to spot what changed. Useful when you're not sure what your app is writing to disk, or when you want to verify that a cache invalidation is actually working.

User Defaults Watcher discovers preference files automatically, displays typed key-value pairs, and polls for changes. If you've ever had a bug caused by a stale UserDefaults value, this is the fastest way to catch it.

Where to get SimToolbox

SimToolbox is available on the Mac App Store. We've got plenty more planned, but right now we're most interested in hearing from you — if there's a simulator workflow that drives you mad, we want to know about it.

Now go delete that xcrun simctl alias from your .zshrc.

SimToolbox is developed by Velocity Engineering Systems Ltd.