S7ddharth builds
Built at Meta Global AI Developer Hackathon · Oct 26, 2026 · Remote

Kizuna is a calm, voice-first app for staying close to the few people who matter most. You talk to it the way you think, in half sentences, and Muse Voice Transcribe writes it live. Muse Spark turns each note into people, dates and promises, so your circle builds itself with nothing to type in. Kizuna then finds one good moment to reach out. On Friday it suggests a family call that everyone can make, outside their quiet hours, in their own time zone, with an idea for the call taken from your notes. One tap drafts a short line in your tone and opens WhatsApp. Family answer from a link with four big buttons: nothing to install, no account. Before you call someone, Kizuna shows three things to remember and one good question, and the day after, it asks once if you talked. Your notes stay on your phone. The family map shares only free times, never location, and every answer is sealed on the device with a key the server never sees. There are no streaks, counters or red badges. Kizuna is built for the close half of your world: the people one time zone or one bus ride away who drift when life gets loud.