Email: onceworks.tools@gmail.com We usually reply within 2 working days.
Products
ProofStamp and MomentNotes, for Chrome and Firefox
ChatCellar, for Chrome
TableSnag and WholePage PDF, for Firefox
How do I activate my license? Your license key is in the receipt email Gumroad sent after purchase.
ProofStamp: open ProofStamp → Settings (the ⚙ in the popup), paste the key and click Activate.
MomentNotes: click the MomentNotes toolbar icon, paste the key and click Activate.
ChatCellar: click the ChatCellar toolbar icon → ☰ to open the library. Scroll down to the Pro box, paste the key and click Activate.
TableSnag: click the TableSnag toolbar icon → ⚙ (Settings). Under License, paste the key and click Activate.
WholePage PDF: click the WholePage PDF toolbar icon → ⚙ (Settings). Under License, paste the key and click Activate.
Activation needs an internet connection, because the key is checked with Gumroad. Only the license key is sent, never your notes, chats, tables or pages.
I lost my license key. Use Gumroad's license key lookup: https://gumroad.com/license-key-lookup. Enter the email you bought with (or your PayPal invoice ID), and Gumroad emails your receipt with the key. Still stuck? Email us your Gumroad order number.
I moved to a new browser or computer. Install the extension there and paste the same license key. The extensions don't limit how many of your own browsers use your key.
MomentNotes notes are stored in each browser and don't sync. Before you switch, download or copy your notes as Markdown, because they won't move over on their own.
ChatCellar chats are stored in each browser and don't sync. Before you switch, make a backup (Library → Export and backup → Back up everything (.json)). In the new browser, use Restore from a backup….
ProofStamp, TableSnag and WholePage PDF keep no captures inside the extension. Your PDFs, PNGs, CSV and Excel files are wherever you saved them.
Does the license need the internet? Only to activate, and for a quick re-check with Gumroad about every 14 days. If a re-check can't connect, your license keeps working for up to 30 days after the last successful check.
Refunds Purchases are made through Gumroad, and Gumroad's terms apply: https://gumroad.com/terms. To ask about a refund, email us with your Gumroad order number.
Why can't ProofStamp capture this page? Browsers don't let extensions run on some pages:
browser settings and internal pages (chrome://, about:, view-source:)
other extensions' pages
the extension stores (Chrome Web Store, addons.mozilla.org)
On those pages the popup says "Your browser doesn't allow extensions on this page." Open a normal website tab and try again.
Where do my files go? To your browser's Downloads folder, named like proofstamp_2026-10-16_21-53-38_page-title.pdf. If your browser asks where to save each download, that setting comes from your browser.
How does the free trial count? You get 3 free captures. A capture counts when you save it. Saving the same capture as both PDF and PNG counts once. Capturing and then discarding it doesn't count. The popup and Settings show how many are left.
What time is on the PDF? The capture time from your computer's clock, in your local time and in UTC. ProofStamp is a documentation tool. It does not independently verify or notarise the time or the content.
Can I remove the "Created with ProofStamp" line? Yes, once licensed: Settings → ProofStamp credit line on PDFs. Trial PDFs always carry the trial footer.
Privacy policy: https://sites.google.com/view/onceworks-tools/proofstamp-privacy-policy
How do I open the notes panel? On a YouTube watch page, click the round teal button (bottom-right) or press Alt+Shift+N.
To change the shortcut in Chrome: chrome://extensions/shortcuts
To change the shortcut in Firefox: about:addons → ⚙ → Manage Extension Shortcuts
To add a note at the current video time, click "Add at current time" or press Ctrl+Enter (Cmd+Enter on Mac).
Where do my notes and files go? Notes are saved in your browser on this computer, per video. The toolbar popup lists every video you have notes for. Download .md saves to your browser's Downloads folder, and Copy Markdown puts the notes on your clipboard.
How does the free download counter work? Notes and Copy Markdown are always free. Downloading a .md file is free for your first 3 videos. A video you've already downloaded stays downloadable, and only new videos count. The popup shows how many free videos are left.
The button doesn't appear. MomentNotes works on youtube.com watch pages only. Reload the page once after installing.
My notes are missing. Notes are saved per video, so open the same video again or check the toolbar popup. Notes don't sync between browsers or computers.
Privacy policy: https://sites.google.com/view/onceworks-tools/momentnotes-privacy-policy
ChatCellar saves your ChatGPT and Claude conversations into a private archive in your browser, so you can search and reread them offline.
Where do I get it? The Chrome Web Store listing isn't live yet. The link will be added here once it's published. Pro is a one-time $19 purchase on Gumroad (no subscription): https://toolsmith170.gumroad.com/l/nahnu
Which sites does it work on? chatgpt.com (and the older chat.openai.com address) and claude.ai. It doesn't run on any other site.
What's free, and what does Pro add?
Free: up to 25 saved chats. The free plan includes:
the library
full-text search
optional auto-save
updating chats you've already saved
restoring a backup
Pro: unlimited chats, plus:
export a chat as Markdown or JSON
"Export all as Markdown (.zip)"
"Back up everything (.json)"
When the free library is full, your saved chats stay readable and searchable, and you can still update them. Only new chats can't be added until you delete one or get Pro.
"Save this chat" is greyed out, or the popup says "Reload this tab once".
That tab was open before ChatCellar was installed or updated. Reload the page once, then click the ChatCellar button again.
If it says it can't find the messages, wait for the chat to finish loading and try again.
If it says "Some replies didn't load on the page", reload the page and save again.
If it still won't save, the site may have changed its page layout. Please email us.
Why can't it save this chat?
The chat has no address of its own yet: for example a temporary chat, or a new chat before it gets its own link. ChatCellar can save only chats that have their own address.
A reply is still being written: you can save now, without that reply, or wait for it to finish.
Only part of a long Claude chat is on screen: scroll to the top and save again, and the earlier messages are added to your copy.
Is anything saved automatically? Only if you turn on auto-save. It's off until you do. With auto-save on, a chat you open is saved after a reply has finished.
Where are my chats stored? Only in this browser, on this computer. There's no account and no cloud copy, and your chats are never uploaded. If you uninstall ChatCellar, your saved chats are deleted. Make a backup first.
How do I back up or export?
Open the library (toolbar icon → ☰). Under Export and backup:
Back up everything (.json) saves your whole archive as one file (Pro).
Restore from a backup… brings it back (free).
Export all as Markdown (.zip) saves every chat as a Markdown file (Pro).
To export one chat: open the chat in the library and click Export .md or Export .json (Pro).
Files go to your browser's Downloads folder.
What isn't saved?
Claude artifacts (the side panel) aren't saved in this version.
Claude's "Thought process" is saved only if you had it expanded on screen when you saved.
ChatCellar is independent and isn't affiliated with OpenAI or Anthropic.
Privacy policy: https://sites.google.com/view/onceworks-tools/chatcellar-privacy-policy
TableSnag copies a table or list from a web page into Google Sheets or Excel, or saves it as CSV or Excel.
Where do I get it? TableSnag is for Firefox only (Firefox 142 or later). Its Firefox Add-ons listing is waiting for Mozilla's review. The link will be added here once it's published. Pro is a one-time $15 purchase on Gumroad (no subscription): https://toolsmith170.gumroad.com/l/nlizhx
How do I use it?
Click the TableSnag toolbar button, then Find tables. Every table and list on the page is highlighted.
Click the one you want.
Copy it for a spreadsheet, copy it as HTML (for Docs, Word or email), or click Download CSV or Download Excel.
What's free, and what does Pro add?
Free: every feature, up to 250 rows per table:
copy
CSV and Excel
lists and cards
collecting a table that runs over several pages
If a table is longer, the free plan saves the first 250 rows and tells you so.
Pro: removes the row limit.
"No tables or lists found on this page."
If the table loads after the page opens, wait a moment and click Scan again.
TableSnag finds:
HTML tables
grids
repeated lists and card grids
tables inside frames from the same website
It can't read tables inside frames from other websites, or tables drawn as images.
"That table is gone. Click Scan again." The page changed after you picked the table, for example after a refresh or new results. Click Scan again and pick it again.
The table is spread over several pages.
Start collecting, then use Auto-collect the next pages. It clicks the site's own Next button for you, up to 50 pages, and you can press Stop at any time.
Or go to each page yourself and click Add this page. Repeated headers and pages you've already added are skipped.
If the site opens a whole new page for each page of results, do this on each one: click Next, click the TableSnag button, then click Add this page.
Some cells start with an apostrophe ('). Cells that start with = or @ would run as a formula in a spreadsheet. TableSnag adds a leading apostrophe to them so they stay plain text.
Why can't TableSnag run on this page? Firefox doesn't let extensions run on some pages:
internal pages (about:)
other extensions' pages
addons.mozilla.org
Open a normal website tab and try again.
Where does my data go?
Copies go to your clipboard, and files go to your Downloads folder.
TableSnag reads a page only when you click its button, and doesn't keep a history of what you copy.
Privacy policy: https://sites.google.com/view/onceworks-tools/tablesnag-privacy-policy
WholePage PDF saves a whole web page as a PDF that looks like the screen, with real text you can search and copy.
Where do I get it? WholePage PDF is for Firefox only (Firefox 142 or later). Its Firefox Add-ons listing is waiting for Mozilla's review. The link will be added here once it's published. Pro is a one-time $9 purchase on Gumroad (no subscription): https://toolsmith170.gumroad.com/l/epatmo
How do I use it? Click the WholePage PDF toolbar button, then Save whole page. It scrolls through the page once so everything loads, then puts your scroll position back. The PDF is saved to your Downloads folder. A progress box shows how far it is and has a Cancel button.
What's free, and what does Pro add?
Free: up to 10 PDF pages per capture, with a small credit line. If the page is longer, the first 10 pages are saved and WholePage PDF tells you so.
Pro: up to 150 pages per capture, and you can turn the credit line off (Settings → Credit line on PDFs).
How do I add the page address and time? The URL and time stamp is off by default. Turn it on in Settings (⚙ in the popup) → URL and time stamp on page 1. Page 1 then starts with:
the page title
the address
the time you saved it, in local time and UTC
Each page footer also shows the UTC time.
The PDF shows cookie banners or headers in odd places. In Settings → Fixed and sticky bars, choose one of these:
show them on the first screen only (the default)
hide them everywhere
keep them on every capture
The file is too large, or not sharp enough. Settings → Image quality: Standard, High (sharper, larger files) or Smaller files. You can also choose A4 or US Letter paper.
"Couldn't capture this page. Reload it and try again." Reload the page, wait until it has finished loading, then click Save whole page again.
"Your browser doesn't allow capturing this page." Firefox doesn't let extensions run on some pages:
internal pages (about:)
other extensions' pages
addons.mozilla.org
Open a normal website tab and try again.
Where does my data go? The PDF is built on your computer and saved to your Downloads folder. Nothing is uploaded, and WholePage PDF doesn't keep copies of the pages you save.
Privacy policy: https://sites.google.com/view/onceworks-tools/wholepage-pdf-privacy-policy
ProofStamp: captures the visible part of the page only, with no full-page scrolling capture. It can't run on browser-internal pages or the extension stores.
MomentNotes: works on youtube.com watch pages only (not Shorts, embedded players or other sites). No sync between browsers. Up to 500 notes per video. No transcripts, AI summaries or video downloading.
ChatCellar: works only in Chrome, on chatgpt.com and claude.ai. Claude artifacts aren't saved. Chats don't sync between browsers or computers.
TableSnag: works only in Firefox. It can't read tables inside frames from other websites, or tables drawn as images. Auto-collect stops after 50 pages.
WholePage PDF: works only in Firefox. Up to 10 pages per capture on the free plan, and up to 150 with Pro.
All: if you uninstall an extension, the browser deletes its stored data (MomentNotes notes, ChatCellar chats, settings and license status). Export or back up first. You can paste your license key again after reinstalling.
Email onceworks.tools@gmail.com with:
The product (ProofStamp, MomentNotes, ChatCellar, TableSnag or WholePage PDF) and its version, which is shown on chrome://extensions or about:addons.
Your browser and version (for example Chrome 140 or Firefox 158) and your operating system.
What you did, step by step, what you expected, and what happened instead.
The exact error message, if one appeared, and a screenshot if you can.
The page type, for example "a YouTube watch page", "a ChatGPT chat" or "a normal website". Please don't send private page content, chat text, passwords or your license key.
We never need your license key to look into a bug. If it's about a purchase, your Gumroad order number is enough.