Hi Product Hunt! I make small Mac apps under Apps by Mo.

Every time my Mac got slow, hot or full, the answer was Activity Monitor and words like swap and memory pressure. So I built What Happened. You say what feels wrong in plain words, and it finds the cause on your Mac and fixes it with your OK.

You don't have to be an expert to fix your Mac. Just have a chat with it.

What it does:

Ask in your own words. "My Mac feels slow, fix it." It checks memory, the processor, heat and every app, names the cause, and shows the plan. Nothing runs until you press. On my Mac it found an iPhone simulator nobody was using that held 4.2 GB, and shut it down in one press.
Ask about the past. "What happened yesterday at 2:30 PM?" It records your Mac every 10 seconds, so the answer has names, not guesses.
Home: one look tells you if your Mac is okay, with the one thing worth doing and the button that does it.
Fix: pick what's wrong (slow, won't sleep, internet, sound, Bluetooth, out of space, search, printer, Dock or Finder stuck). It checks first, then offers the one fix that helps.
Menu bar: a live view of right now, and the common fixes one click away.
Your day as one line, with every spike named, and a week view of what keeps coming back.
Clean only what's safe, with every row saying why. Uninstall apps along with everything they left behind. All of it goes to the Trash, with Undo.
Space: your whole disk as one ring, biggest first.
Startup: it tells you when something new adds itself to startup.
For developers: a read-only MCP server, so Claude Code or Codex can ask how your own app behaved.

No account, no analytics, and your history stays on your Mac.

It's free for 7 days with every feature and no card. Then it's $13.99 once, with free updates, on up to 3 Macs. Needs macOS 14 or later.

I'd love to hear what it catches on your Mac, and what it gets wrong. I'll be here all day answering.