Riff

Riff is a free Chrome extension that helps you reply on X, LinkedIn, Facebook and Instagram. You paste your rough point. Gemini Nano, the AI built into Chrome, writes a fresh reply for that exact post. You read it, edit it if you want, and press send yourself.
Riff also answers your DMs in LinkedIn Messaging, Messenger on facebook.com and Instagram Direct. When a chat is new, it writes the first message. It can draft your own posts too. Drop in rough notes, ask for changes in plain words, and pick a hook you like. It can also turn notes into an X thread or an Instagram caption, and reshape one post for another site in the right length.
You set how it sounds. Choose how smart, how salesy and how bold the reply should be, and set tone and length with simple dials. Tell Riff once who you are and how you write, and it follows that voice. You can keep separate voices for brands you run, so you can post as yourself or as your company. Each draft is checked against your recent replies, so it does not repeat itself.
Everything runs on your computer. There is no account, no API key, no server and no monthly bill. Your notes, drafts and history stay in Chrome storage on your machine. Riff never posts or sends anything for you. It fills the reply, comment, message or post box and stops there, so you stay in control of every word that goes out.
Riff is useful for founders, marketers, consultants and creators who reply a lot. Reply to posts in your field without starting from a blank box. Leave real comments on LinkedIn instead of writing "Great post". Answer DMs faster without agreeing to a time or price for you. Write a first message to a new contact, cold or warm.
Riff needs desktop Chrome 138 or newer on Windows 10 or 11, macOS 13 or later, Linux or a Chromebook Plus. You also need about 22 GB of free disk for the one-time model download, and a GPU with more than 4 GB of video memory, or 16 GB of RAM and 4 CPU cores. Riff is built by Michael Zima at Zima Media OÜ in Tallinn, Estonia.