Name: Last Letter
Brand: DEPLOYR
Price: 189 USD
Availability: PreOrder

Picture this

Who it is for

Grace writes to her daughter for her 18th birthday. Last Letter encrypts it, stores it permanently, and releases it on schedule or if Grace misses a yearly check in.

Two ways to own it

What you get

Base$189

$47 deposit to reserve

Letter composer, encryption, check in switch contract, recipient claim flow

You choose: chain
You choose: name and logo
You choose: accent color

Customfrom $1,500

Built around you

Reshape it entirely: new features, your flows, your brand end to end, integrations you need. We scope it with you.

Everything in Base
Custom features and design
Priority build

Why it is new

What exists today, and what this does differently

Why own your own

Legacy letters with dead man switches are live; recipient wallets on unlock and warmer UX are the differentiators.

Closest things out there

FinalCapsule runs consumer letters with check-in release to trusted contacts, Sarcophagus is an onchain dead man switch with Arweave storage, and Nopalito stores memorial time capsules onchain.

Checked with web searches in October 2026. A search is not proof that nothing similar exists, and the market moves fast, so we recheck before every build.

What it unlocks

The human in it

Preserves your voice for the people you love.

The Regatta Board

Races it can enter

grant · Arbitrum Foundation · rolling

Arbitrum Foundation Grants / DAO programs

rolling

Official page ↗

Existing projects OK

Their rule on existing code: Existing projects OK

What you own

The whole app, not a starter kit.

The complete Last Letter app: people write letters that are encrypted on their phone and open for named readers on a date or after silence plus trusted confirmers, with plans and checkout built in.

Base price · $189

The user app, complete

Every buyer gets the same finished app. Basic branding and copy changes come through a quick form.

Three step onboardingHome

Shown once: write in your own words, choose when it opens, only they can read it.

Next action and circleHome

One clear next step, years to the release date, and the reader, confirmers and first reader with faces.

Letter composerWrite

Recipient picker, handwritten style editor, draft saved and encrypted on the device.

Voice notesWrite

Recorded notes inside the letter. Gated behind the Family plan.

Date or silence releaseWrite

Open on a chosen date, or after a missed check in, grace period and confirmer agreement.

Confirmers who hold the brakesWrite

Pick trusted people; silence alone never opens a letter.

Seal with checkoutWrite

Sealing goes through the USDC checkout, then a share card that shows the seal, never the words.

Visible seal and versionsLetters

Release date, confirmers, version hash and a new version flow that keeps the old hash on record.

One line a yearLetters

Add a yearly line and re-seal. Gated behind the Family plan.

Claim page and birthday simulationLetters

Preview what the reader sees and jump to the release day.

Yearly check inKeeper

One tap resets the hourglass; simulate an ordinary year or a quiet one.

Reminder channels with bounce pauseKeeper

SMS, email and WhatsApp (gated); a bounced number pauses the countdown and opens a fix task.

Plans, receipts and settingsMe

Pricing from the owner paywall, onchain versus never onchain receipts, adult reads first, permissions.

Open the full app demo

Add-on

Owner console

Your admin side: revenue, paywall editor, users, rules and the agent log.

Revenue and paywall editorRevenue

Recurring revenue, one letter sales, USDC payments, payment methods, live tier and gate editing.

Rules, keeper log and roadmapRules

Check in interval, grace period, confirmers needed, bounce pause, gas sponsoring; plus the Agent log and priced Roadmap.

Top-up

Growth and referrals

Referral and growth mechanics, switched on when you are ready to grow.

Growth loops and cohortsGrowth

Hospice writing evenings, confirmer invites, gift letters, claim day and writer referrals.

The money path, built in

How it earns for you

Writing drafts is free. Writers pay once to seal a letter or monthly for the family plan, and care partners such as hospices sponsor seats. Readers never pay.

DraftFreeWrite and save drafts, preview the claim page, add recipients

One letter$19 onceSeal one letter, date or silence release, two confirmers, yearly check in

Family$4 a monthUnlimited letters, voice notes, one line a year, WhatsApp reminders

Care partners pay per sponsored seat (from $49 a month). Storage and check in gas cost cents and can be sponsored by the owner.

Prices are yours to set. Illustrative, not a promise of income.

Growth loops, built in

How it spreads

Confirmer invites: every letter introduces two trusted people to the product
Hospice and community writing evenings that onboard writers in a batch
Gift a sealed letter for birthdays, graduations and new babies
Sealed share card that shows the seal and date, never the words
Writer to writer referral codes worth a free Family month for both

Roadmap · build the next phase with us

Where it goes next

v1 included

The full writer app

Composer with on device encryption
Date or silence release with confirmers
Yearly check in, grace period, bounce pause
Recipient claim page and receipts
Paywall and plans

Included

Care partner portal

Hospice and estate lawyer accounts
Sponsored seats by invite code
Guided writing sessions with prompts
Swahili and French interface

Add-on from $450

Family archive

Letters across generations in one family tree
Video notes with permanent storage
Printed keepsake on release day
Offline backup card

Add-on from $900

For investors and grant reviewers

The pitch, ready

Letters to the future that open for the people you love, at the moment you chose, and never sooner.

Problem: People want their voice to reach their family at the right moment. Letters sit in drawers or email drafts nobody can open, and nothing both keeps the words private and guarantees they arrive.

Solution: Letters are encrypted on the writer's phone, stored permanently, and released by a small contract on a date or after silence plus confirmer signatures. Readers claim with an email sign in.

Why now: Permanent storage, threshold key networks, sponsored gas and email wallets make a private, reliable release practical for people who have never used crypto.

Market: Parents, grandparents, people facing illness, and the hospices, estate planners and community groups who support them.

The ask: Pilot with one hospice and one estate planning practice, and grant funding from the Arbitrum Foundation programme.

Funding is never guaranteed. Check each program's rules.

For hackathons and demo days

Your 2 minute demo

Home: meet Grace, a night nurse in Nairobi, writing to her daughter Amani for her 18th birthday.
Write: draft the letter, choose 14 March 2035, and pick Otieno and Njeri to hold the brakes.
Write: sealing is paid, so unlock One letter through the USDC checkout, then seal and see the share card.
Letters: show the visible seal, the receipt, and skip to the birthday to see Amani open it.
Keeper: check in for the year, then go quiet and watch a bounced SMS pause the countdown.
Owner Agent: read how the keeper asked a confirmer gently and added a two channel rule.
Owner Revenue: change the Family price in the paywall editor and preview the writer Plans sheet.
Owner Growth and Roadmap: run a hospice writing evening, then request the care partner portal.

Many hackathons require code written at the event. See the Regatta Boardfor each race's rule.

Make it entirely yours

Custom work from $1,500: your own release rules, a hospice or law firm branded deployment, extra languages, or integration with an estate planning CRM. Scoped on a call.

Custom from $1,500

BLUEPRINT

Why it matters and how it really works

The need

People want their voice to reach the ones they love at the right moment, even if they are not there. Today letters sit in drawers, email drafts nobody can open, or with a relative who might lose them. Nothing both keeps the words private and guarantees they arrive.

What exists and what is new

This exists. FinalCapsule already runs consumer letters released to trusted contacts after missed check ins, Sarcophagus is an onchain dead man switch with Arweave storage, and Nopalito stores memorial time capsules onchain. Research verdict: exists, low novelty. What this app adds is warmer UX on top of that pattern: an email sign in that gives the recipient a wallet at unlock, a date or silence trigger chosen per letter, confirmers who must agree before any early release, a bounced contact pausing the countdown, and a yearly line that grows the letter.

The data it runs on

The letter, voice notes and photos, encrypted on the writer's device. Release rules (date, check in interval, grace period, confirmers). Check in timestamps. Contact channels for reminders. Recipient and confirmer emails, kept off chain.

1.The mission

Make sure the words you mean to leave behind reach the people you love, at the moment you chose, and never sooner.

2.Why people can't resist it

One line a year Each yearly check in asks what happened that the reader should know. The letter grows into a family record.

The seal you can see Anyone can verify the letter is still sealed and when it opens. Nobody can read it early.

A gift with a date Writers share that a letter exists, not what it says. Friends ask how, and write their own.

3.How it works for real

Sign in: Privy email or passkey sign in creates an embedded wallet on Base or Arbitrum for the writer, and later for the recipient at claim time.

Encrypt on device: The letter is encrypted in the browser. Ciphertext goes to Arweave (permanent) and its hash is recorded onchain.

Switch contract: A small contract stores the release rules, takes check in transactions (gas sponsored by a paymaster) and emits a release event on the date or after silence plus confirmer signatures.

Key release: The decryption key is held by a threshold network such as Lit Protocol, with an access condition that reads the contract. It decrypts only for the named recipient's account after release.

Keeper: A scheduled worker sends reminders by email, SMS and WhatsApp, detects bounced channels, pauses the countdown and asks confirmers gently. A small model (for example Claude Haiku) drafts the reminder wording; it never sees the letter.

Claim flow: The recipient gets an email, signs in, and the letter decrypts on their device. Optionally a copy goes to a named adult first.

4.Cost per use and pricing

Per letter: Arweave storage about $0.01 to $0.05 for a few MB with voice notes; each check in on Base costs well under $0.01 in gas, sponsored; reminder messages about $0.01 to $0.05 each with SMS. A writer with one letter and yearly check ins costs well under $1 a year. 1,000 active writers: roughly $50 to $150 a month including hosting and messaging.

One letter $19 once

One sealed letter, date or silence release, two confirmers.

Family $4 a month

Unlimited letters and recipients, voice notes, yearly lines, WhatsApp reminders.

Care partner Custom

Hospices, estate lawyers and community groups offer it to the people they serve.

5.Growth loop

Each letter has recipients and confirmers, who learn the product exists in a trusted, personal way. Birthdays and claims are emotional moments people talk about, and writers share the sealed card without the contents.

6.Risks and guardrails

False release: Silence is not death. Long grace periods, multiple channels, a bounced channel pausing the clock, and confirmers who must agree all reduce early release.

Lost keys: If the key network or storage fails, letters are lost. Use permanent storage and a mature threshold network, and let writers export an offline backup.

Emotional harm: Some letters hurt. Allow a gentle preview note, an adult beside a young reader, and the family's choice of timing.

Legal: This is not a will. Say so clearly and never handle assets or legal instructions.

Abuse: Someone could send hostile content. Recipients can decline and report, and writers are identified accounts.

7.Build order

Email sign in and in browser encryption
Arweave upload and switch contract on Base
Date release with threshold key access
Yearly check in with email reminders and grace period
Two confirmer flow for early release
Recipient claim page

8.Where this is going

Now
Letters to a child at 18, released on the date or after confirmed silence.
Next
Yearly lines, voice and video, and family vaults with many writers.
Later
Hospices and community groups help people record their stories for the ones they leave behind.
The world it changes
Nobody's last words depend on a password or a drawer. The people we love hear us when it matters.

Costs and tools are estimates at the time of writing. General information only, not legal or financial advice.

OWNER PLAYBOOK

Own it, then chart your voyage

Nine routes from one vessel. Tap a port to open its chart.

Why own Last Letter

The things we most want to say often live in a notes app that nobody will ever find. Own Last Letter and you run the quiet, durable place for those words, from your wallet and brand, with encryption and release rules people can trust. The families, the trust and the stewardship are yours.

What’s stopping you?

“What if the letter unlocks by mistake?”

The check in switch sends several reminders before release. Explain every step clearly and let writers set long grace periods.

“What if the app shuts down?”

Letters are stored permanently and the release runs by contract, but you still owe users a clear plan for what happens if you stop running the site. Write it down publicly.

“I can't code.”

You do not need to. Last Letter arrives working, deployed from your own wallet with a written guide for every step. You will click, paste and fill in names. If you ever want a change you cannot make, the custom option or a freelancer can handle it, but the first launch needs no code.

“Is it really mine?”

Yes. The contract is deployed from your wallet on Base, the code sits in your own git repo, and the name and brand are yours. DEPLOYR does not hold your keys or take a cut of what Last Letter earns. If you stop paying anyone tomorrow, the app keeps running on your wallet.

“What if nobody uses Last Letter?”

That is the most likely early outcome, and it is fixable. The paths below start with you as the first user, then ten real parents, families and anyone who wants to leave words for later you can name today. If ten people you message do not care after you have shown it to them, you have learned something useful in a week instead of a year.

The million-dollar ladder

A yearly plan per writer (letters stored and check ins run), plus gift plans for families and partnerships with estate planners. This ladder is a target, not a promise.

$40

$1,000

$24,000

$84,000

First 10 users

10 writers

$4 each

Proof it works

200 writers

$5 each

Real business

3,000 writers