Chrome extension
MP4 to MP3
from $5Extracts clean audio from any MP4. The conversion runs on your machine, so the file itself is never uploaded.
Learn moreKobaltstack
We build simple browser extensions and web apps that help people get everyday tasks done faster.
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
JPG to PDF
from $2.99Combines images into one PDF, with control over page size, order and margins.
Learn more
Chrome extension
HEIC to JPG
from $3Converts iPhone HEIC photos to JPG in the browser, in seconds.
Learn more
Chrome extension
Save Image As Type
from $2.99Saves any image as PNG, JPG, WebP or PDF from the right-click menu, whatever the original format.
Learn more
Chrome extension
Quick Unzip
from $2.99Opens ZIP archives in the browser and extracts the files you need, without a desktop app.
Learn more
Chrome extension
PDF to Markdown
from $6Turns a PDF, from your computer or a URL, into clean Markdown you can preview and copy.
Learn more
Chrome extension
TTS Reader
from $7.99Reads any web page, PDF or Google Doc aloud, with natural voices and live highlighting.
Learn more
Chrome extension
600% Sound Volume
from $3Boosts the audio of any tab up to six times the system maximum, with an optional equalizer.
Learn more
Chrome extension
YouTube NonStop
from $1.89Dismisses YouTube's “Continue watching?” prompt so long playlists keep playing.
Learn more
Chrome extension
Audio to Text Transcription
from $9.99Transcribes speech from the microphone, a tab or a file, powered by Whisper.
Learn more
Web app
AI Note Taker
from $12.99Records and transcribes meetings from the browser tab, with no bot joining the call.
Learn more
Web app
MediaScribe
from $7.99Turns any YouTube link into a transcript with timestamps. Exports TXT, SRT and VTT.
Learn more
Web app
ViSearch
from $9.99Searches inside a video by word or meaning and returns a transcript, timestamps and a summary.
Learn more
Chrome extension
Chrome Reader Mode
from $2.99A clean, ad-free reader view for any article, with a dark theme and PDF export.
Learn more
Chrome extension
Floating Notes
from $4Sticky notes that stay on top of any web page or app, and work offline.
Learn more
Chrome extension
Text Editor
from $1.89A plain-text notepad in a tab: type, edit and save as .txt.
Learn more
Web app
PDF Highlighter
from $6Highlights and annotates PDFs online: upload, mark up, save.
Learn more
Chrome extension
Flowchart Maker
from $6Draws flowcharts and data-flow diagrams right in the browser.
Learn more
Chrome extension
NotebookLM Importer
from $3Sends open tabs and YouTube videos to NotebookLM in bulk, instead of one by one.
Learn more
Chrome extension
Link Grabber
from $3Collects every link on a page or across tabs, filters them and exports the list.
Learn more
Chrome extension
Broken Link Checker
from $5Scans a page for dead links, 404s and redirects, color-codes them and exports to CSV.
Learn more
Chrome extension
Phone Simulator
from $4Previews any site as it looks on iPhone, iPad and Android screens.
Learn more
Chrome extension
Pixel Measurement
from $5An on-screen ruler for measuring distances and elements in pixels.
Learn more
Chrome extension
Html2Email
from $4An HTML editor for Gmail and Yahoo Mail: paste or write the code, preview it and insert it into the message.
Learn more
Web app
Fontastic
from $1.89Generates styled Unicode text for Instagram, X and TikTok bios and posts.
Learn more
Chrome extension
Authenticator
from $2.99Time-based 2FA codes, stored encrypted in your browser and available offline.
Learn more
Chrome extension
Clear Cache Chrome
from $1.89Clears cache, history, downloads and cookies in one click.
Learn more
Chrome extension
QR Code Reader
from $1.89Scans QR codes from a page, an image, your camera or a shared screen.
Learn more
Figma plugin
Sheets2Figma
from $8Fills Figma layers with data straight from Google Sheets.
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.