Issue 290
Sep 23, 2025

This week's SwiftLee Weekly covers:

• Apple Docs for LLMs
• Supporting async calls in defer
• Physics-driven moti

Enjoy this week's SwiftLee Weekly!

THIS WEEK'S BLOG POST

​App Store Optimization: Real-world Best Practices​

I started sharing this in last week's What I'm working on and it turned out way to much to share in just this newsletter. This week's article is a true piece of art if you like reading real-world journeys of app developers. I'm sharing my experience and results of RocketSim's App Store optimizations, including do's, don'ts, and personal learnings.

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SWIFT EVOLUTION

An overview of last week's Swift Proposal state changes. Check them out when they're in review, as it's your opportunity to influence the direction of Swift's future.

WHAT I'M WORKING ON

Next-level Xcode Simulator Screenshots

One of the first features of RocketSim has been the ability to create screenshots and recordings. Back in the days, the Simulator didn't offer any functionality to do this. Even though you can now do this directly, Xcode's Simulator still does not support everything you would expect:

• Recordings dont include audio
• There's no way to show touches or device bezels
• You can't apply a custom background
• Captures are not valid & accepted by App Store Connect

This is why many iOS developers choose RocketSim for their screenshots & recordings.

While the feature worked great for years, I always had an itch that I kept pushing forward. I'm honestly not sure why, as I've been so excited over the past days for what I'm building next!

Soon, you'll be able to create screenshots directly from the Simulator that look as follows:

You'll be able to configure the aspect ratio (it's 16:9 for the above example), padding, shadow, and background.

In fact, you can already download RocketSim from the Mac App Store and access the custom background for captures:

While it already looks great, I'm still in a huge challenge for this week. Creating screenshots is pretty doable, but the recordings are way harder. This is because simctl does often return a portrait recording, even if the device has been in landscape. On top of that, I'll have to make sure touches are placed properly, like in this example recording.

Either way, it's absolutely worth it. First responses on social have been highly motivating, like "It’d be a killer feature that could kill a few startups at least." or Sean Allen's repost. While I'm not aiming to sherlock anyone, I'm highly motivated for this technical challenge.

Have a great week, and stay tuned!