Prevon's AI runs on your device, right where the notes already live. Ask it something you half-remember and it answers from what you wrote. By default nothing you ask — or it answers — leaves the machine. No account, and the only key is yours.
Windows · macOS · Linux · Android · iOS
Library
BIO 201 — exam 3 review
2:14 PMMitochondria → ATP production, Krebs cycle diagram. Prof said unit 4 is ~40% of the final, so start there.
Cell biology — week 3 lecture
YesterdayCristae fold up to pack more surface area for aerobic respiration.
Study group — Monday
MonPriya’s trick for remembering the mitochondria steps — ask her to redo that before the exam.
Reading — cellular respiration
Aug 30Glucose breaks down into roughly 32 ATP before a cell can use it.
4 notes match. Scroll, or open the top one.
Locked on your device
Only you hold the key — we can't read them
01 · Write
Class notes, group-project brain dump, 2am thoughts. Same box, same speed, no setup.
02 · Encrypt
Your notes get scrambled before they ever travel. We store the scramble, never the message.
03 · Ask
Search by meaning, not just keywords. Auto-filed as you write. None of it leaves your laptop or phone.
No account. No credit card. Free forever.
Every notes app makes you do the tidying — decide the folder, name it, drag it, remember to do it. Prevon takes that job away. Save a note and it is already where it belongs, before you think about it.
And it is honest about what it cannot do. Where the AI is not confident, it asks instead of guessing — and where nothing fits, it tells you plainly rather than dumping the note somewhere wrong.
BIO 201
The exam is mostly unit 4
Prof said unit 4 is ~40% of the final, so start there. Mitochondria → ATP synthase production, Krebs cycle diagram.
Where each step happens
Write, or press/for commands
Write a note, save it, and it lands in the right folder — no prompt, no naming, no dragging. On by default; turn it off whenever you like.
Close match, it files it. Vague match, it shows you the options and waits. No match at all, it says so and files nothing — it never invents a folder to look clever.
The model that reads your note runs on your own device. Your text is not uploaded to make the decision, and there is no server that could make it for you.
Most notes apps give you a list and call it structure. Prevon gives you a real tree — folders inside folders, each with its own colour, joined by rails that show what belongs to what. Your notes end up somewhere you can actually see.
You are never made to file anything by hand — but when you want to shape it yourself, the shape holds. Deep trees stay legible instead of collapsing into indentation.
No artificial ceiling and no flat tags pretending to be structure. Nest a folder under a folder under a folder — the tree keeps its shape and you keep your bearings.
Pick a colour per folder and it shows on the folder, its glyph and its count — so BIO 201 looks like BIO 201 everywhere, not one more indented grey line in a wall of indented grey lines.
A hairline runs from each folder down to the ones inside it, the way a code editor draws its file tree. You can see what belongs to what without clicking anything.
Each folder carries how many notes live inside it, tinted to its own colour. You can feel where your notes actually are before you open a thing.
Collapse what you are not working in and the tree folds away to a clean outline. Open one branch and only that branch lights up with colour.
Most AI notebooks send your notes to a server. Prevon's AI runs on your device — it searches, sorts, and answers without your notes ever going anywhere.
Auto-filed into the right folder as you write. Search matches exact words and what you meant, together — not one or the other.
Nothing is ever deleted without asking. Sort a note into a folder as you write — that part is instant. Anything bigger, like re-filing or merging, waits for your yes, and every action it takes is logged where you can see it.
The AI that reads and organizes your notes runs on your own device, not in our cloud. Nothing to upload, nothing sitting on someone else’s machine. Want zero network of any kind? Turn on Air-Gap Mode and it blocks every outbound connection the app can make — including the device-to-device sync path.
All of this runs on your device. There is no cloud AI in this build, even if you paste in your own API key.
The part everyone dreads about switching notes apps is the moving. Prevon takes that job too. Your old app has an export button — that is the hardest step. Point Prevon at what it makes and your notes come over, sorted into folders, encrypted on your device, with a plain report of anything it could not bring.
Not one note at a time — the entire export, in one go. Drop in the folder or the .zip your old app produced and Prevon reads the lot.
Grant it one folder and it works out what is inside — Obsidian, Evernote, Notion, Apple Notes, Bear, Google Keep, plain text — and shows you what it found before it imports a thing.
The common case is a folder holding exactly what you meant to bring: it shows that, everything already selected, and one button. Anything it cannot read is named in the report, never quietly dropped.
Import a second time and it updates what changed instead of copying everything twice — so you can move over at your own pace without making a mess.
Your notes are encrypted on your own machine as they come in. The export you hand it is read and sealed right there — no server in the middle, and your originals are left untouched.
Not a policy promise — a structural one. Encryption happens on your device, with a key only you hold.
100%
encrypted on your device
0
times we can read your notes
0
trackers, analytics or ads
1
key, and it never leaves you
When a breach happens, it happens to plaintext. Ours isn't. Lose your Recovery Seed and we cannot recover your vault — that's not a flaw, it's the whole point.
The whole app — encrypted notes, on-device AI — is free with no account. You only pay if you want your notes synced between devices.
Free
$0
No account, no card, no catch. The full vault.
Ghost Sync
$4/month
Sync between your devices that stays locked the whole way. Ships after the beta.
The beta is the security test. Every seat goes to someone whose job is to try to break the vault — and what they find gets fixed before it ships to anyone else.
No account, no trackers, no analytics. The server never holds a key that opens your notes.
A PGP-signed warrant canary, a public key to verify it, and an open credit page for security reports.
You don't need to be a spy to use Prevon. Open it with Face ID — and your 12-word Recovery Seed gets you back in if you ever lose the device.
Quick unlock
EverydayFace ID or fingerprint to open the app. Fast, no retyping.
Full unlock
RecoveryYour Recovery Seed opens the vault on a new device, or after a reset. Only you hold it.
Step-up check
Opt-inTurn on a re-auth gate so sensitive changes need your phrase again, even on an unlocked device.
Prevon is invite-only while the vault is hardened. Every beta seat goes to someone testing it against a real attacker — apply, and you're in the queue.
