Sumi vs Lachlan
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Sumi
This app helps you reduce phone usage by setting timers for breaks. It alerts you if you touch or move your device during the break, aiming to boost productivity and mental well-being.
- Timed phone breaks
- Movement alerts
- Productivity enhancement
- Mental health improvement
- Simple interface
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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
Lachlan
This app acts as a digital padlock, blocking distracting applications on a set schedule. It requires users to provide a reason before granting temporary access, encouraging mindful usage and accountability.
- Scheduled app blocking
- Reason-based access grants
- Personalized accountability
- Screen time history trends
- Streak system for engagement
- Offline functionality
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Every app blocker is one tap from off. This one asks why. Lachlan is a small, deeply opinionated padlock who blocks your most distracting apps on a schedule you set, and then makes you explain yourself before he lets you back in. WHY THIS WORKS WHEN NOTHING ELSE HAS Most blockers are a wall you learn to climb in about three seconds. Lachlan is a conversation you have to have with a character who remembers what you said you wanted, and wants to know why you're doing this instead. Most of the time, you find you don't have a good reason to get into these distracting apps. HOW IT WORKS 1. Pick your problem apps. Social media, games, news, whatever's eating your time 2. Set a schedule, time limit, location, or timer to block your apps the way you want. 3. Try to open a blocked app and you'll hit the shield instead. 4. Open Lachlan and make your case. Depending on how good your reason is, he'll grant you 5, 15, or 30 minutes. 5. He keeps score. The fourth unlock of the day does not go like the first. HE ACTUALLY REMEMBERS YOU When you set up, Lachlan asks why you're cutting back and what you'd do with the time you got back. Then he brings it up. "You said you wanted to finish studying" lands very differently at 11pm than a generic productivity notification. He knows your name, your reasons, and exactly how many times you've caved today. Most blockers are stateless. Lachlan is not, and that's the whole difference. ALSO INCLUDED - Trends tab showing you screen time history - Streak system to keep you engaged each day - A home screen widget showing Lachlan's current mood - Custom block screens - Works offline, on a plane, in a tunnel, anywhere Subscription is required for access to the above features. https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Screenshots
Verdict
The clearest difference is review sentiment: Lachlan at 100% against Sumi's 0%. Lachlan also leads on rating (5.0 vs 3.0) and ratings volume (8 vs 2). Sumi's advantage is monetization model (free vs subscription) and iOS requirement (16.0 vs 26.0). On price, update cadence, ads and in-app purchases there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Sumi sells 3 in-app purchases, starting at $5.99 per month and Lachlan sells 3 in-app purchases, starting at $3.99 per 7 days. Whichever you choose, the download price is not the number that matters.
Lachlan holds the better App Store score, 5.0 against 3.0. Both are backed by a comparable volume of ratings — 2 and 8 respectively. Written reviews point the same way: 0% of Sumi's written reviews are positive against 100% of Lachlan's.
Sumi ships an update every 5 days, Lachlan weekly. The most recent releases landed on November 3, 2026 and November 10, 2026 respectively.
| Parameter | Sumi | Lachlan |
|---|---|---|
| Price | Free | Free |
| Rating | 3.0 (2 ratings) | 5.0 (8 ratings) — better |
| Positive reviews | 0.0% of reviews | 100.0% of reviews — better |
| Number of ratings | 2 | 8 — better |
| Update frequency | Every 5 days — better | Weekly |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free — better | Subscription |
| Devices | iPhone | iPhone, iPad — better |
| Requires iOS | 16.0 — better | 26.0 |
| Further details — not scored | ||
| Size | 10 MB | 34 MB |
| Age rating | 4+ | 9+ |
| Developer | David Park | ND Enterprises |
Customer experience
Sumi
Lachlan
In-app purchases
Sumi
- Sumi Pro Monthly$5.991 Month
- Sumi Pro Annual7 Days trial$24.991 Year
- Sumi Pro Lifetime$49.99
Lachlan
- Weekly Subscription3 Days trial$3.997 Days
- Lachlan Monthly Subscription$7.991 Month
- Lachlan Yearly Subscription7 Days trial$69.991 Year









