AI replies for Mac,
in any inbox.

FlowIn is an AI reply generator that lives at your cursor instead of in a separate window. Press one key in Mail, Slack, or any chat, and it reads the conversation and offers three ways to answer. Pick one and it writes the full draft where you were already typing.

Download for Mac

Free to download. Apple Silicon, macOS 13.3 or later.

See an AI reply written in place

FlowIn predicts your intents in every chat and inbox: pick one, or hand it your rough draft.

FixRephraseTranslateShortenExpandHumanize
S
Sam
Great meeting you today! Let's grab coffee soon.
Reply to Sam

Three keystrokes, not three windows

01

Press the key

Tap the FlowIn badge or the right Option key in any inbox or chat. No window opens, nothing is copied out.

02

Pick how you want to answer

FlowIn reads the thread and offers three ways to reply, so you choose the intent rather than editing a draft you did not ask for.

03

Accept the draft

The one you pick becomes a full reply in your voice, in the field you were already typing in. Change it, or send it.

Already wrote something? Reshape it

The same key works on text you have already written. Select it, and FlowIn rewrites it in place rather than handing you a second draft to copy back.

  • Fix
  • Rephrase
  • Translate
  • Shorten
  • Expand
  • Humanize

Why not a menu bar app

Most AI reply tools on the Mac are a web page or a menu bar panel. The work they leave you is the copying: message out, answer back, window switched twice, and the thread lost in between.

FlowIn reads the conversation where it already is and types into the field your cursor is in. It is the same layer that does autocomplete for Mac, so predicting your next words and drafting a whole reply are one tool rather than two subscriptions.

  • Mail
  • Gmail
  • Outlook
  • Slack
  • Messages
  • WhatsApp
  • Discord
  • Telegram
  • Signal
  • LinkedIn
  • Notion
  • X

Where the conversation goes

A reply generator reads the whole conversation, so this is worth being exact about. Drafting a reply runs on a cloud model: the thread and the draft are sent off your Mac, used to produce the answer, and not retained unless you opt in. Autocomplete is the piece that can run fully on-device, predicting your next words with nothing transmitted. Both paths are set out in the privacy policy.

Questions

Is there an AI that writes replies in any Mac app?
Yes. FlowIn works at the system level rather than inside one client, so the same shortcut drafts a reply in Mail, Slack, Messages, WhatsApp, Discord, or a Gmail tab in your browser.
How is this different from a menu bar AI assistant?
A menu bar or web tool means copying the message out, pasting it in, then pasting the answer back. FlowIn reads the conversation in place and writes into the same field you were already typing in, so nothing leaves the window.
Does it work in Gmail and Slack in the browser?
Yes. FlowIn works in browser text fields as well as native apps, so a Gmail tab in Chrome, Safari, or Arc behaves the same as Mail.app.
Can it match my writing style?
The draft is written to follow the tone of the thread and the way you normally answer, and you can reshape it before sending with Fix, Rephrase, Shorten, Expand, or Humanize.
How many AI replies do I get for free?
Ten a day on the free plan, after a 14-day unlimited trial. Pro removes the limit for $14/month, or $10/month billed annually.
Does my conversation get sent to a server?
Yes, for replies. Drafting from a thread runs on a cloud model, so the conversation and the draft are processed off your Mac. They are used to produce the answer and are not retained unless you opt in. Autocomplete is the part that can run entirely on-device.
Download for Mac

More on autocomplete for Mac, what FlowIn costs, and common questions.