kobaltstack
Pricing

Kobaltstack

We build simple browser extensions and web apps that help people get everyday tasks done faster.

See the tools Contact us
About us

Small tools, serious time savings

A collection of focused browser extensions and web apps. Each one takes care of a single everyday task, from converting a file to transcribing a call.

  • Each product does one job well, with no setup and no learning curve.
  • AI is used where it saves real minutes: transcription, reading aloud, summaries.
  • Everything runs in your browser. Fair prices and a 14-day money-back guarantee.
The tools

Our products, one job each

Chrome extensions, web apps and Figma plugins. All of them are used every day and take one click to get started.

Chrome extension

MP4 to MP3

$5 / month

Extracts clean audio from any MP4. The conversion runs on your machine, so the file itself is never uploaded.

Learn more
Chrome extension

Save Image As Type

$1.99 one-time

Saves any image as PNG, JPG, WebP or PDF from the right-click menu, whatever the original format.

Learn more
Chrome extension

Quick Unzip

$2.99 / month

Opens ZIP archives in the browser and extracts the files you need, without a desktop app.

Learn more
Chrome extension

PDF to Markdown

from $9 / month

Turns a PDF, from your computer or a URL, into clean Markdown you can preview and copy.

Learn more
Chrome extension

600% Sound Volume

$2.99 / month

Boosts the audio of any tab up to six times the system maximum, with an optional equalizer.

Learn more
Chrome extension

Audio to Text Transcription

from $6.99 / month

Transcribes speech from the microphone, a tab or a file, powered by Whisper.

Learn more
Web app

AI Note Taker

from $2 one-time

Records and transcribes meetings from the browser tab, with no bot joining the call.

Learn more
Web app

ViSearch

from $5 one-time

Searches inside a video by word or meaning and returns a transcript, timestamps and a summary.

Learn more
Chrome extension

Chrome Reader Mode

$2.99 one-time

A clean, ad-free reader view for any article, with a dark theme and PDF export.

Learn more
Chrome extension

Floating Notes

$2.99 / month

Sticky notes that stay on top of any web page or app, and work offline.

Learn more
Chrome extension

NotebookLM Importer

$2.99 / month

Sends open tabs and YouTube videos to NotebookLM in bulk, instead of one by one.

Learn more
Chrome extension

Link Grabber

$6 / month

Collects every link on a page or across tabs, filters them and exports the list.

Learn more
Chrome extension

Broken Link Checker

$2.90 / month

Scans a page for dead links, 404s and redirects, color-codes them and exports to CSV.

Learn more
Chrome extension

Phone Simulator

$7.90 / month

Previews any site as it looks on iPhone, iPad and Android screens.

Learn more
Chrome extension

Html2Email

$4.99 / month

An HTML editor for Gmail and Yahoo Mail: paste or write the code, preview it and insert it into the message.

Learn more
Chrome extension

Clear Cache Chrome

$3 / month

Clears cache, history, downloads and cookies in one click.

Learn more
Chrome extension

QR Code Reader

$3 / month

Scans QR codes from a page, an image, your camera or a shared screen.

Learn more
Chrome extension

Messages Deleter

$9.99 one-time

Clears your old messages from Discord chats and channels in a few clicks.

Learn more
Figma plugin

BGRemover

from $3.99 one-time

Removes image backgrounds inside Figma in one click.

Learn more
Figma plugin

Sheets2Figma

$2.99 / month

Fills Figma layers with data straight from Google Sheets.

Learn more
Figma plugin

Frame Saver

$2.99 / month

Exports Figma frames in bulk, in the formats you choose.

Learn more
Contact

Get in touch

Questions, partnership ideas or feedback on a tool: write to us. We reply to every message, usually within two business days.

Open in your mail app