StudyJunkie vs Kusari
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
StudyJunkie
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StudyJunkie turns every app-opening moment into a study opportunity. Before you can open social media, games, or any app you choose, you must answer a quiz. Powered by iOS Screen Time (Family Controls), StudyJunkie puts a smart learning gate between you and distraction. HOW IT WORKS 1. Select apps you want to restrict 2. When you try to open them, a quiz appears 3. Answer correctly to unlock the app for your chosen duration QUIZ CATEGORIES - Math: auto-generated calculation problems (Jr. High / High School level) - English Vocabulary: 3,700+ words with audio (Jr. High, High School, TOEIC) - Pharmaceuticals: brand name and generic name matching - Custom: create your own questions for any subject FEATURES - 7 difficulty levels (Jr. High 1-3, High School 1-3, TOEIC) - Word memory tracking: words answered correctly 3+ times are marked learned - Combo system: keep your streak going! - ZONE mode: triggered at 5+ combos for a special effect - Detailed stats: total answers, accuracy, best streak, and more - Custom quiz creator: add any question you need - Bilingual UI: Japanese and English supported - No data collection: your study data stays on your device
Kusari
This app uses behavioral economics to build a daily English learning habit. It employs a commitment device where users risk losing money if they miss their daily tasks, encouraging consistent practice through financial stakes rather than willpower. Daily activities include reading, shadowing, and AI conversation, taking 15-20 minutes.
- Commitment device with financial stakes
- Daily reading, shadowing, and AI conversation
- 15-20 minute daily tasks
- Behavioral economics principles applied
- Dynamic skill level adjustment (CEFR A1-C2)
- Tiered pricing based on daily achievement
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意志が弱いんじゃない。逃げ場が、あるだけだ。 Kusariは、毎日の英語学習を「鎖」で習慣に変えるアプリです。読む、話すの2ステップ、1日15分ほど。意志の力ではなく、設計で続けます。 コミットメント・デバイス(自分への約束を仕組みで守る装置)の研究をもとに設計しています。Yaleの研究者らが立ち上げたstickKなどで知られる手法です。Kusariは同大学と提携・監修関係にはありません。 料金は、続けた日数で決まります。 通常価格 月¥5,000(自動更新)。直近30日の達成日数によって、翌月のご請求が5段階で変わります。 ・24日以上 ¥0 ・18〜23日 ¥1,000 ・12〜17日 ¥2,500 ・6〜11日 ¥4,000 ・5日以下 ¥5,000(通常価格) 日数に比例して安くなるのではなく、上の5段階で決まります。 割引の適用には、更新日の前にアプリ内で申請の操作が必要です(Appleの仕様上、自動では適用できません)。アプリが更新前にお知らせします。 最初の7日間は、登録なしでお試しいただけます。8日目にご登録いただくと、そこから30日間の無料トライアル(初回のみ)が始まり、最初のご請求はその後です。 お試し期間7日分の記録は、ご登録後のアカウントには引き継がれません。 サブスクリプションは自動更新です。期間終了の24時間前までに、iPhoneの「設定」>ご自身のApple ID>サブスクリプションから解約できます。 今は三日坊主でも大丈夫です。続けられる自分に変わるための仕組みだけ、用意しました。
Screenshots
Verdict
The clearest difference is in-app purchases: StudyJunkie at none against Kusari's 1. Kusari's advantage is iOS requirement (15.1 vs 18.0). On price, update cadence, ads and device support 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. Kusari sells 1 in-app purchase, starting at $29.99 per month. StudyJunkie asks for nothing beyond the download.
StudyJunkie ships an update every 2 weeks, Kusari every 10 days. The most recent releases landed on September 28, 2026 and August 23, 2026 respectively.
| Parameter | StudyJunkie | Kusari |
|---|---|---|
| Price | Free | Free |
| Positive reviews | — | 100.0% of reviews |
| Update frequency | Every 2 weeks | Every 10 days — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | — | Free with in-app purchases |
| Devices | iPhone, iPad | iPhone, iPod |
| Requires iOS | 18.0 | 15.1 — better |
| Further details — not scored | ||
| Size | 10 MB | 123 MB |
| Age rating | 4+ | 4+ |
| Developer | KAZUHIRO KAMAKURA | RYUTA ABE |
In-app purchases
StudyJunkie
No in-app purchases
Kusari
- Kusari Monthly1 Month trial$29.991 Month





