How to use Zen

First start

Accept the terms, set an app password (or unlock with biometrics) and choose a name.
No phone number, no e-mail: your key is your address, and your QR code is that address.
Set up a way back right away: make a key copy and, once you have 4 friends, a recovery circle of friends who can help you get your account back. There is no “forgot password” e-mail, because no company holds your account.

Open Settings → Invite and show your QR code. Your friend scans it, or the other way round.
No camera? Copy invitation gives a link; the page it opens installs Zen or opens it.
Set how close each friend is: casual friend, friend or close friend. Only you see it.

YouFriend

Friend online: the message goes straight to their device, sealed end to end.

YouMailboxesFriend

Friend offline: sealed copies wait on the devices of up to six of their friends and are handed over later.

YouOutbox

Nobody reachable: the message waits in your outbox and is retried for up to 14 days.

A mailbox sees only ciphertext. Devices that stay online, like a computer in the tray, are preferred.
Icons under each message show exactly where it is.

Groups work like chats and have a Board for posts.
Photos, videos, files, voice notes and GIFs; react, reply, edit, forward, delete for everyone.
You choose who may invite you to groups.

Post for the people you choose. Your feed is in order; no algorithm.
A public post can travel to friends of friends, up to three steps. Each reader chooses how far they look: Friends, 2nd degree (default) or 3rd degree.
A short-video section works the same way.

Over Bluetooth Zen shows friends who are close. Strangers see only a random nickname and a rough distance.
No internet? The same Wi-Fi, Wi-Fi Direct or Bluetooth connect friends’ devices directly.
The alarm calls your close friends, even from a locked Android phone.

Notification content: sender and content, sender only, or just a notice, for all chats or for one.
Friendship levels decide who sees your friend list and statuses, and who may invite you.
Every profile field has its own audience: public, friends, close friends or only you.

The app password locks Zen, and Zen locks itself after a while. A locked Android phone still receives, sealed, until you unlock.
An emergency wipe password typed on the lock screen quietly erases the data.
Ways back to your account: another device with it, a full account copy (an encrypted file), a key copy (paper or file), or your recovery circle of 4 to 6 friends: 2 of them with your password, or 4 without it. If none of these is set up, the account cannot come back.

One account can run on several devices; they keep each other up to date.
On the old device choose Add a second device. On the new one scan its QR code and compare six digits.
Several accounts on one device are possible, hidden ones too.

The user guide explains each part with pictures. It is written in English.