Comparison

Diet Lights vs Yakusoku.

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Diet Lights

This app helps you track your weight and diet progress using a simple traffic light system. It allows you to log morning and evening weights, monitor trends, and record daily factors like mood and meals.

Highlights
  • Traffic light weight progress system
  • Morning and evening weight logging
  • Weight trend graphs
  • Calendar view of daily progress
  • Intermittent fasting timer
  • Mood and meal logging
  • BMI calculation
Features
Read full description

Diet Lights is a simple weight tracking app that helps you record your morning and evening weight and see your diet progress at a glance with traffic light colors. What’s New - Dark Theme The entire app now supports dark mode. Choose System, Light, or Dark in Settings for a more comfortable experience. - Premium Water Widget Log your daily water intake right from Home and see your progress toward your daily goal at a glance. Water tracking is also available in Calendar, making it easier to build healthy habits. - Intermittent Fasting Timer Choose 12h, 16:8, 18:6, 20h, or a custom fasting schedule. Start fasting from the home widget, check progress with a circular timer, and keep your fasting history. - Diary Log your daily mood, meals, condition, and weight-related factors with emoji tags such as dining out, late-night snacks, period, or constipation. - Precise Weight Entry Record your weight with up to 2 decimal places for more accurate weight management and body weight tracking. - Better Goal Tracking Set a target weight, check your progress in 10 stages, and restart your goal from today whenever you want a fresh start. - Morning/Evening Cutoff Time Customize when the app separates morning weight and evening weight based on your lifestyle. Why Diet Lights? For healthy dieting and yo-yo weight prevention, it is helpful to consistently check the difference between your evening weight and the next morning’s weight. Instead of complicated calorie counting, Diet Lights shows your daily progress with simple traffic light colors. Main Features - Traffic Light System Green light: Evening-to-morning weight difference of 1 kg or more Yellow light: Small weight change Red light: Weight increase - Weight Trend Graph View your weight graph by 1 week, 1 month, 3 months, 6 months, or 1 year. Compare morning and evening weight changes and see your target weight line. - Calendar View Check daily traffic lights, morning weight, evening weight, weight changes, BMI, and more on the calendar. Review your monthly diet pattern at a glance. - BMI and Body Mass Index Set your height to check BMI. Choose between WHO standard and Asian standard for a more realistic reference. - Target Weight Set a realistic target weight and track remaining weight, progress rate, and your next stage visually. - Reminders Get notifications for morning and evening weight measurement times. You can also set fasting end reminders. - Backup and Restore Premium users can safely store data with iCloud backup and restore weight records, diary entries, and fasting history when changing devices. - Passcode Lock Protect your personal diet records with a 4-digit passcode lock. How to Measure Your Weight - Morning: After waking up and using the bathroom - Evening: After dinner and before going to bed - Measure at similar times every day - Track not only weight, but also morning/evening differences, meals, fasting time, and condition Premium Features Upgrade to Diet Lights Pro to get: - No ads - Unlimited access to all features - iCloud backup and restore - More convenient personal record management Recommended For - Anyone looking for a simple diet app - Anyone who wants weight management without calorie counting - Anyone who wants consistent weight tracking - Anyone who wants to prevent yo-yo dieting - Anyone using intermittent fasting or a fasting timer - Anyone who wants to manage BMI and target weight - Anyone building healthy habits with calendar, reminders, and diary features - Anyone who needs visual feedback for diet motivation Dieting starts with small daily records. Start building a healthy diet habit with Diet Lights today. To protect your privacy, all data is safely stored on your device. Premium users can choose iCloud backup. If you have any questions, please feel free to contact us. Terms of Service : https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

Yakusoku.

Features
Read full description

一日に、自分に、一つだけ約束する。 これは、自分との約束を守る力を鍛えるためのアプリです。 ◆ たった一つのシンプルな習慣 朝、自分に一つだけ約束を書きます。 「今日、私は自分に約束する:___」 ただ一行。 夜、その約束と向き合います。 守れたのか。守れなかったのか。 ○か×を、自分で押します。 たったそれだけ。 ◆ 4つの記号が、あなたの日々を記録する ○ 守れた × 守れなかった △ 向き合わなかった(判定せず日付境界を越えた日) — 約束しなかった日 これらの記号が、履歴に静かに積み重なっていきます。 それは、あなたと自分の関係の、嘘のない記録です。 ◆ 取り消せない 一度確定した判定は、後から変更できません。 ゲームのようにリセットできない。 過去は、重い。 だからこそ、今日の一つの約束に、意味が宿ります。 ◆ 白と黒だけの、静かなデザイン 通知もカラフルなアニメーションもありません。 バッジも、連続記録のプレッシャーもありません。 ただ、あなたと、今日の約束と、向き合う時間だけ。 ◆ プライバシー完全保護 すべてのデータは、あなたのiPhone内にのみ保存されます。 外部に送信されることは一切ありません。 データ収集ゼロ、ネットワーク通信ゼロ、広告ゼロ。 ◆ こんな人に ・毎日の小さな積み重ねを大切にしたい人 ・自分との信頼を取り戻したい人 ・ミニマルで静かなアプリを好む人 ・シンプルな内省の時間が欲しい人 今日、あなたは自分に何を約束しますか。

Screenshots

Diet Lights4 screens
Yakusoku.4 screens

Verdict

The call

The clearest difference is in-app purchases: Yakusoku. at none against Diet Lights's 3. Yakusoku. also leads on ads (none vs shown) and update cadence (weekly vs every 2 weeks). Diet Lights's advantage is device support (3 vs 1) and iOS requirement (15.1 vs 17.0). On price 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Diet Lights sells 3 in-app purchases, starting at $1.99 per 7 days. Yakusoku. asks for nothing beyond the download.

UpkeepUpdate frequency

Diet Lights ships an update every 2 weeks, Yakusoku. weekly. The most recent releases landed on November 6, 2026 and October 31, 2026 respectively.

Scorecard5 real differences · 5 level
Diet Lights versus Yakusoku.: the parameters behind the verdict, then further details
ParameterDiet LightsYakusoku.
PriceFreeFree
Rating4.5 (2 ratings) — better—
Positive reviews83.3% of reviews—
Number of ratings2 — better—
Update frequencyEvery 2 weeksWeekly — better
AdsYesNo — better
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
DevicesiPhone, iPad, iPod — betteriPhone
Requires iOS15.1 — better17.0
Further details — not scored
Size94 MB1 MB
Age rating4+4+
DeveloperHouse201Shosuke Sato

In-app purchases

3 purchases

Diet Lights

Subscriptions3
  • 프리미엄$1.997 Days
  • Premium Monthly$2.991 Month
  • Premium$12.991 Year
None

Yakusoku.

No in-app purchases

Questions

Is Diet Lights free?
Diet Lights is free to download, with in-app purchases available.
Is Yakusoku. free?
Yakusoku. is free to download, with no in-app purchases.
Do Diet Lights or Yakusoku. have ads?
Diet Lights shows ads; Yakusoku. does not.
Which is updated more often, Diet Lights or Yakusoku.?
Diet Lights ships an update every 2 weeks, and Yakusoku. weekly. Most recently, Diet Lights was updated on November 6, 2026 and Yakusoku. on October 31, 2026.

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