Sumi: Deep Work Focus

About this app

The most beautiful thing an app can do is get out of your way. Sumi sits quietly on cream paper, holds your attention for an hour, and asks for nothing back. Set a length. Put your phone face down. Pick it up before the time is done and the session breaks — not as a punishment, but as a commitment kept. No ads. No notifications. No streaks-as-slot-machines. No weekly subscription trap. Just deep work, and the quiet record of the hours you've given it. — THE RITUAL — Set an intention and a length. Put the phone down. Sumi keeps watch: lift it, or leave the app, and the session ends. When the time is held, the line completes, your lifetime hours grow, and the session is logged. Silent while you work. Quietly rewarding when you finish. — A CALM LEDGER, NOT A GAME — The number that only goes up: your lifetime hours focused. A streak, if you want one. A week that fills, a line that climbs. No characters to feed, no points, no dark patterns. Progress you can feel, with nothing engineered to hook you. — MADE FOR DEEP-WORK PEOPLE — For writers, developers, designers, students of a craft — anyone who already romanticizes focus and resents apps built to fracture it. Graphite and cream. Monospace. Paper grain. A single calligraphic mark. — PAY ONCE — Your focus shouldn't be a recurring charge. Sumi is free to use, with an optional one-time Lifetime unlock (or a subscription, if you prefer) for custom lengths, full history and trends, themes, and session intentions. Put the phone down. Pick the work up. ——— Privacy Policy: https://dayonefoundry.com/sumi/privacy Terms of Use (EULA): https://dayonefoundry.com/sumi/terms

Small wording refinements and a calmer finish to each session.

Momentum comes from crawler snapshots for the tracked storefront. “Viral growth signal” means unusually fast recent rating gains; it is an indicator, not download data.

1. First observed Sep 11, 2026 · 7:01 AM Free