DevPrep vs System Design Refresher
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
DevPrep
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You have the coding skills, but can you explain them clearly under pressure? DevPrep is the Offline-First AI Interview Coach designed specifically for Software Engineers. Stop practicing in your head. Start speaking. DevPrep simulates the pressure of a real interview, records your answer, and uses an advanced on-device AI engine to grade your response against ideal technical answers. WHY DEVPREP? • AI GRADING ENGINE: Our local vector-based AI analyzes your speech for technical accuracy, logic, and clarity. Get a score (0-100) instantly. • PRIVACY & FAST: All grading happens securely on your device. Your voice recording is processed locally. • ZERO FLUFF: 250+ curated questions from the current tech industry standards. 5 SPECIALIZED TRACKS: - SOFT SKILLS & LEADERSHIP - DATA STRUCTURES & ALGORITHMS (pro) - SYSTEM DESIGN ARCHITECT (pro) - MODERN FRONTEND ENGINEERING (pro) - BACKEND & DISTRIBUTED SYSTEMS (pro) FEATURES: - Realistic "Interviewer" Audio to simulate pressure. - "Silent Mode" for practicing on the go (multi-choice questions). - Local progress feature to track your mastery. - Offline-First architecture (Privacy focused).
System Design Refresher
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System Design Refresher is a free study companion for software engineers preparing for system design interviews. WHAT'S INSIDE • 30+ system design articles covering distributed systems, databases, caching, and more • Engineering blogs from top tech companies (Google, Meta, Stripe, Airbnb, and more) aggregated in one place • AI-powered flashcards with spaced repetition • Ask AI to summarize or explain any article in plain language • Favorites, reading progress tracking, and custom RSS feeds FEATURES • Works offline — articles download for reading without internet • Dark mode, font customization, and text size controls • Face ID / Touch ID lock for privacy • Sign in with Google or Apple, or use as a guest with no account required
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Verdict
The clearest difference is in-app purchases: System Design Refresher at none against DevPrep's 5. DevPrep's advantage is update cadence (every 2 days vs monthly) and iOS requirement (15.1 vs 26.2). On price, 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. DevPrep sells 5 one-off in-app purchases. System Design Refresher asks for nothing beyond the download.
DevPrep ships an update every 2 days, System Design Refresher monthly. The most recent releases landed on September 24, 2026 and September 12, 2026 respectively.
| Parameter | DevPrep | System Design Refresher |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 2 days — better | Monthly |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.1 — better | 26.2 |
| Further details — not scored | ||
| Size | 149 MB | 18 MB |
| Age rating | 4+ | 4+ |
| Developer | Thieu Khue | Saurabh Sharma |
In-app purchases
DevPrep
- Backend Scale pack$9.99
- Data Structure & Algorithms pack$9.99
- System Design pack$9.99
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- Frontend Engineering pack$9.99
- Unlock all Pro Packs$29.99
System Design Refresher
No in-app purchases
Questions
Is DevPrep free?
Is System Design Refresher free?
Do DevPrep or System Design Refresher have ads?
Which is updated more often, DevPrep or System Design Refresher?
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