The problem

There is no safe, personal digital route for the letter, the voice recording or the video people want to leave for their loved ones after they die — social media accounts were not designed for this.

The solution

An app with letters, audio and video, a book of reconciliation, final wishes and a PDF "Legacy File". Its most striking part is the "Digital Vault": a legacy file encrypted with a 50-round SHA-256 key derivation and opened with a three-word passphrase (for example APPLE-CLOUD-SEA).

The question that set the scope was not "how many features" but "who am I forced to trust". Recordings stay on the device and the vault file travels through a channel the user chooses; there is no server sitting in between holding the file. That simplified the product technically and made its most critical promise — "nobody but me can read this" — defensible.

Technology

Expo / React Nativeexpo-cryptoexpo-audio / expo-videoAsyncStorage6-Language i18n

A detail worth highlighting

The vault file and its passphrase are deliberately shared through separate channels — the person sends the legacy file while still alive and passes on the passphrase separately. The moment the family downloads the app and opens the file with the passphrase, the app introduces itself as well.

Behind an emotional need sits a serious engineering decision: the LockGate overlay approach preserves the navigation position after unlocking — so even at their most vulnerable moment, the user feels the app has not reset itself.

Let's talk about a similar problem

If there is a product carrying sensitive data, or work where a promise of trust needs a technical backbone, an email is enough.