a menu bar app for macOS

EMS

“explain me shit”

Select anything on your screen, press a hotkey, and get it explained in plain language, written for a beginner.

Download for Mac

macOS 14 or newer · works on Apple Silicon and Intel · free

After downloading, follow the three-minute setup. macOS will put up a warning; the setup explains it.

What it does

It sits in the menu bar. No Dock icon, no window. It shows up only when you press one of its keys.

⌥⌘E

Explain selected text

Select text anywhere — a code editor, a web page, a database client — and press the keys. A small floating panel explains it.

⌥⌘S

Explain a screenshot

Drag a box around part of the screen instead. Good for charts, error dialogs and diagrams.

Ask follow-ups

Type a question in the same panel. It remembers the conversation, so “what does that part mean” works.

  • Keeps a history of your last 15 explanations, on your Mac.

It uses your own AI key

EMS has no AI of its own. It connects to a free account you make with Groq or Google Gemini (or paid Anthropic, or any OpenAI-compatible service). That is why it is free, and why there is no EMS account to sign up for. Nobody pays for anyone else’s usage.

Templates

A template decides what kind of explainer EMS is: how it talks, what it assumes you know, what it focuses on. Six come with it. You can edit any of them, or write your own.

  • SQL
  • Maths
  • Code
  • Driving theory
  • Plain English rewriter
  • Polish grammar

SetupAbout three minutes. Do the steps in order.

  1. Step 1: Install

    Open your Downloads folder. If you see EMS.zip instead of EMS, double-click it to unzip.

    Drag EMS into your Applications folder. Don’t open it yet.

  2. Step 2: Get past the security warning

    macOS will say EMS “is damaged” or “cannot be opened”. It isn’t damaged.

    That is what macOS says about any app that isn’t signed with a paid Apple developer account. EMS isn’t, and it isn’t from the App Store. The fix is one line.

    1. Open Terminal: press ⌘Space, type Terminal, press Return.
    2. Copy this line, paste it into Terminal, press Return.
    xattr -dr com.apple.quarantine /Applications/EMS.app

    Nothing will appear to happen. That’s correct — now open the app normally from Applications.

    What the line does: it removes the “downloaded from the internet” tag macOS put on EMS, which is what triggers the warning. It touches nothing else.

    Rather not use Terminal?

    Open EMS and let macOS block it. Then go to System Settings → Privacy & Security, scroll down, and click Open Anyway next to the message about EMS. Confirm when asked.

  3. Step 3: Two permissions

    The first time EMS opens, its setup window walks you through both, with a button for each that takes you to the right place in System Settings.

    • Accessibility — lets EMS read what you’ve selected. It does this by pressing ⌘C for you.
    • Screen Recording — only needed for the ⌥⌘S screenshot key. Skip it if you only want text.

    macOS may ask you to quit and reopen EMS after granting one of these. Let it.

  4. Step 4: A free AI key

    Go to console.groq.com/keys, sign up, and create a key. It’s free, needs no credit card, and takes about a minute.

    The key starts with gsk_. Groq shows it only once, so copy it before closing that page.

    Or use Google Gemini, also free

    If you already have a Google account, go to aistudio.google.com/apikey, sign in, and click Create API key. No credit card. That key starts with AIza.

    One difference: on Gemini’s free tier, Google may use what you explain to train its models. Groq doesn’t. If that matters for what you’ll be explaining, pick Groq.

    Paste whichever key you made into EMS’s setup window. Done. Select some text and press ⌥⌘E.

Privacy

Short version: what you explain goes only to the AI service you picked.

  • What you explain is sent to the AI provider you chose, using your own key. On Google Gemini’s free tier specifically, Google may use it to train their models. Groq and Anthropic do not.
  • Once a day EMS asks GitHub whether a newer version exists. That shows GitHub your IP address and macOS version — nothing about what you explain. You can switch it off in Settings.
  • Nothing else leaves your Mac. Your key is kept in the macOS Keychain. History and templates are stored locally.