Full transparency — in plain English, with the real technical details underneath.
The one-sentence version: every app is just a web page that your browser saves onto your
device, and everything you create is stored in your browser's own private storage on that same
device — nothing is ever uploaded to us or anyone else, because there is no server to upload to.
App Hub is a collection of Progressive Web Apps (PWAs). A PWA is a normal website that a
modern browser can also install like an app. There is no app store, no download of an .exe
or .apk, and nothing to approve beyond your browser's own "Add to Home Screen" prompt.
Step 1
You open an app
You visit the app's page in your browser, just like any website.
Step 2
You choose "Install"
Use the Install button, or your browser's "Add to Home Screen" / "Install app" menu item.
Step 3
The browser saves it
Your browser copies the app's files into its own local cache and adds an icon to your home screen or desktop.
Step 4
It opens full-screen
Tapping the icon launches the app in its own window — no address bar, like a native app.
Each app is a single self-contained page plus a small icon set and a helper file called a
service worker (more on that next). A tiny file called a manifest
(manifest.webmanifest) tells your device the app's name, icon and that it should open
full-screen. That's the entire "installer."
Nothing runs with special privileges. An installed PWA has exactly the same
limited permissions as a web page. It cannot read your files, your other apps, or anything on your
device that you don't explicitly hand to it through a file picker.
2 Why it keeps working offline
When you first open an app, its service worker — a small script the browser runs in the
background — saves a copy of the app's files (the page, styles, scripts and icons) into a private
on-device store called the Cache Storage. After that, opening the app loads those saved files
directly from your device instead of the network.
Turn off Wi-Fi and the apps still open and run.
They load instantly, because nothing is being fetched over the internet.
The service worker only ever caches files from this site — it can't fetch or cache anything from another website.
3 Where your information is stored
Everything you create — notes, passwords, spreadsheets, designs, 3D models, plans, custody records —
is saved in your browser's own storage on the same device you're using. We never see it because
it never leaves your machine. The specific storage mechanisms:
localStorage
A per-site key–value store built into every browser. Most apps keep your documents and settings here. It's private to this site and to your device — other websites can't read it.
Cache Storage
Holds the app's own files so it works offline (see above). Managed by the service worker.
In-memory only
Some sensitive values (like a Vault's unlocked encryption key) live only in the page's memory while it's open and vanish the instant you lock it or close the tab.
Files you export
When you press Export, Save or Download, the file is written to your device's Downloads folder by your browser — you choose where it goes.
Storage is sandboxed per origin. Every app on this site shares the same origin
(this website), so they can share small conveniences like your light/dark preference —
but no other website anywhere can reach into this storage, and these apps can't reach into any other
site's storage either. That boundary is enforced by the browser itself.
4 How the sensitive apps encrypt your data
Apps that hold secrets — Vault (passwords) and locked notes in Notes — encrypt your
data before it's written to storage, using your browser's built-in Web Crypto engine.
The plain, readable version never touches the disk.
Cipher
AES-GCM with 256-bit keys — a modern, authenticated encryption standard. "Authenticated" means tampering is detected, not just hidden.
Key from your password
Your master password is stretched into an encryption key with PBKDF2 using 210,000 rounds of SHA-256 and a random per-vault salt. This makes password-guessing attacks extremely slow.
Fresh randomness every time
Every single encryption uses a brand-new random 12-byte value (an "IV"), so re-saving the same data never produces a reusable pattern.
Recovery key
Vault also wraps your data key with a random recovery key file you save at setup. If you forget your master password, that file lets you set a new one — without it or the password, the data is unrecoverable, even by us.
What's stored
Only the encrypted blob. Titles, notes, one-time-code secrets — all of it is inside the ciphertext. There is no plaintext copy anywhere.
We could not read your Vault even if we wanted to. The key is derived from a
password only you know and is never sent anywhere. This is the same category of encryption used by
banks and password managers — running entirely inside your browser.
5 What leaves your device answer: nothing
Once an app's files are cached, it makes no network requests at all in normal use. To be
concrete, here's what is not present anywhere in this project:
No analytics or telemetry of any kind.
No trackers, advertising, or fingerprinting.
No cookies.
No accounts, logins, or sign-ups.
No external scripts or fonts loaded from other companies' servers — every file is served from this site.
No back-end server that could receive your data — the site is plain static hosting.
The only time your browser talks to the network is when you deliberately open or update an
app (fetching its files from this site), or click an external link you chose to click (for example a
map link). Even those links are set to send no referrer information. Your browser also enforces
a strict Content-Security-Policy on every page that blocks all connections to any other
server — so even in the unlikely event of a bug, your data has nowhere external to go.
6 How updates reach you
When we improve an app, the service worker notices the new version the next time you open it, quietly
downloads the updated files, and swaps them in. The Hub shows a small "updated — refresh" note when a
new version is ready. You never install anything manually, and an update can only ever replace the
app's program files — it never touches the data you've created.
7 Moving to a new device & backups
Because your data lives on one device, apps that hold important data include an Export / backup
button that writes everything to a single file you control:
Vault exports a fully encrypted backup file — it still needs your master password to open on the new device.
Notes, Sheets, Custody Calendar, Design, 3D CAD, Planner and others export a project or backup file you can move by AirDrop, USB stick, email to yourself, or any method you like.
On the new device you open the same app and use its Import button.
You are always in control of the transfer. The file goes where you send it —
we're never in the middle.
8 Removing an app or wiping your data
Uninstall the app like any app (long-press the icon → Remove, or your browser's app settings).
Clear its data anytime from your browser's site-settings for this site ("Clear data"), which erases the local storage and cache.
Because nothing was ever uploaded, deleting it on your device deletes all of it — there is no copy elsewhere to chase down.
9 Security measures we've put in place
Beyond "we don't collect anything," the apps are hardened so that a malicious file or link can't be
used to attack you:
Content-Security-Policy on every page — the browser only runs this site's own code, forbids loading anything from other servers, and blocks any attempt to send data off your device.
No-referrer policy — external links reveal nothing about what you were doing.
Clickjacking protection — pages refuse to be embedded inside other websites.
Strict output escaping — anything you (or an imported file) types is treated as text, never as code, so a booby-trapped backup file can't run a script.
Import validation — colors, names and other imported values are checked against safe patterns before use.
Vault auto-locks after a period of inactivity and the moment you switch away from the tab; copied passwords are cleared from the clipboard automatically.
External links open safely — the new tab has no access back to the app it came from.
10 Don't take our word for it — verify
You can confirm all of this yourself:
Go offline. Turn off Wi-Fi/data and use any installed app — it keeps working, proving it isn't calling home.
Watch the network. Open your browser's Developer Tools → Network tab and use an app. After the first load you'll see no outgoing requests during normal use.
Verify the behavior. Open your browser's developer tools on any app: the Network tab shows every request the page makes (for most apps: none after loading), and all running code is inspectable on your own device. What you see is exactly what runs.
Check the storage. Developer Tools → Application → Local Storage shows exactly what's saved, right there on your device.