Skip to content
Work

UnslowFind Out Why Your Mac Is Slow

Company
Founder-built Mac app
Period
2026
Role
Founder. Product, design, native macOS engineering, launch
Shipped
unslow.app, notarized by Apple and on sale
Visit unslow.app

Context

Mac memory utilities sell a big free-memory number and a Clean button. The button forces macOS to throw away its cache, the number rises for about a minute, and the Mac pays it back in disk reads. macOS keeps RAM full on purpose, and free memory does not predict a slow Mac. Memory pressure does, along with how fast the Mac is paging to disk.

Landing page, with the app's overview
The Unslow landing page: the headline 'Every slow Mac has a reason. Unslow finds it.' above the app's Overview window, showing memory at 64% under warning, 2.6 GB of swap, a startup disk 98% full, ranked recommendations, and the menu bar popover listing the apps using the most memory.

The problem

Build a Mac utility that tells the truth, one that finds the specific, lasting reasons a Mac is slow and fixes only what can really be fixed.

What I did

  1. Measured what actually predicts slowness. Memory pressure, swap traffic and free disk are read from the same kernel counters Activity Monitor and vm_stat use, so nothing is estimated.
  2. Put the evidence one click away. Every finding opens to the raw readings behind it, because the promise is that the numbers can be checked.
  3. Went after the disk, since a nearly full disk is what turns memory pressure into stalls. Unslow frees caches that developer tools rebuild on their own, from Xcode build data to npm and Homebrew, and never recommends removing personal files.
  4. Left out the button the category is built on. There is no Clean Memory button and no system-junk rule, because both only move a number for a minute.
  5. Designed the app around an instrument gauge. The menu bar item is about a third the width of a typical memory widget and takes its color from the kernel's own pressure level.
  6. Built it natively in Swift for Apple silicon, signed with a Developer ID and notarized by Apple, in under 4 MB with no Electron.

Methods and tools. Swift, SwiftUI, AppKit, Swift Charts, Next.js, Polar

What changed

Live at unslow.app as a one-time $39 purchase for Apple silicon Macs on macOS 14 or later, with 14-day refunds. Designed, engineered and shipped solo.

  • Native Swift, under 4 MB
  • Reads the same counters as Activity Monitor
  • One-time purchase, notarized by Apple