Comparison

Neptune vs Decoded

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

Head to head
About

Neptune

Prepare for USCG COLREG and OOD exams with a comprehensive study system. Features AI tutoring, interactive 3D visuals for lights and shapes, and a complete question bank with intelligent test modes and progress tracking.

Highlights
  • AI-powered tutor for rule explanations
  • Interactive 3D lights and shapes trainer
  • Official USCG question bank
  • Verbatim memory trainer
  • Intelligent exam simulator modes
  • Advanced progress tracking
  • Offline study capability
Features
Read full description

PASS YOUR USCG COLREG & OOD EXAMS WITH CONFIDENCE Neptune: Navigation Rules is the only modern study system that combines the official USCG Question Bank with an AI Tutor, interactive 3D Visual Training, and verbatim cards. Whether you are an Ensign preparing for OOD Phase 1 or a Captain refreshing for a renewal, Neptune replaces heavy textbooks with a smart, pocket-sized coach. NEW: VERBATIm MEMORY TRAINER Level up recall: hide key phrases and type them back to prove you know the rule, not just the letter. Adaptive drills: auto-submit when blanks are filled, with instant feedback and retries to lock in weak spots. Inline citations: jump straight from a missed phrase to the exact rule text. 3D LIGHTS & SHAPES TRAINER Stop memorizing static flashcards. Interactive 3D Models: Rotate vessels to see lights and shapes from any angle. Quiz Mode: Answer questions based on target angle, vessel ID, cardinal direction, and rules of the road. AI-POWERED REFERENCE Don't just memorize the answer—understand the Why. Ask Neptune: Chat with an AI trained specifically on COLREGS and over 500 maritime court cases. Instant Explanations: Get plain-English breakdowns for every question with citations to the rules and cases. Legal Context: Using the court cases see how rules are adjudicated in the real world. COMPLETE USCG QUESTION BANK & BOOK Official Pool: Full access to Inland and International questions. Smart Citation: Every question is linked directly to the specific Rule it tests. Custom Tags: Add your own notes, highlights and rule references. INTELLIGENT TEST MODES Exam Simulator: Mimic the real test by creating presets with precise filters for question number, specific words to be omitted, and rules. Or enable the Smart algorithm to dish you out trouble questions. Study Mode: Filter by "Least Confident" to drill the questions you get wrong. Daily Challenges: Keep your streak alive with quick, timed quizzes to build a daily study habit. ADVANCED PROGRESS TRACKING Confidence Scores: Visualize your mastery of every Rule based on SM-2 Algorithm. Heat Maps: Instantly see if you are weak on "Steering & Sailing" or "Sound Signals." Detailed History: Review past attempts to track your improvement over time. THE MODERN STANDARD Offline Ready: Study in the SCIF or underway—no internet required. Dark Mode: Fully optimized for night watch study sessions. Cloud Sync: Start on your iPhone, finish on your iPad.

About

Decoded

Features
Read full description

Decoded translates confusing social situations into clear, honest answers. When you can't read the room — a friend going cold, mixed signals from someone you like, a group chat that suddenly went quiet — your social coach Ash breaks down what's actually happening and tells you exactly what to do next. No guessing. No spiralling. Just clarity. - Decode what people actually mean - Understand the signals you keep missing - Know exactly how to respond - Build real social confidence over time - Track your streak and level up as you improve - Go Pro for unlimited sessions Stop overthinking. Start understanding. Terms of Use: https://www.trydecodedapp.com/info/terms Privacy Policy: https://www.trydecodedapp.com/info/privacy

Screenshots

Neptune4 screens
Decoded4 screens

Verdict

The call

The clearest difference is in-app purchases: Neptune at none against Decoded's 2. Neptune also leads on iOS requirement (13.0 vs 15.0). 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Decoded sells 2 in-app purchases, starting at $6.99 per month. Neptune asks for nothing beyond the download.

UpkeepUpdate frequency

Neptune ships an update every 2 days, Decoded daily. The most recent releases landed on September 8, 2026 and September 14, 2026 respectively.

Scorecard2 real differences · 8 level
Neptune versus Decoded: the parameters behind the verdict, then further details
ParameterNeptuneDecoded
PriceFreeFree
Rating5.0 (13 ratings) — better—
Positive reviews100.0% of reviews—
Number of ratings13 — better—
Update frequencyEvery 2 daysDaily — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree—
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS13.0 — better15.0
Further details — not scored
Size101 MB10 MB
Age rating4+4+
DeveloperBrice BrownMATTHEW JAMES COLEBORNE

In-app purchases

None

Neptune

No in-app purchases

2 purchases

Decoded

Subscriptions2
  • Decoded Pro$6.991 Month
  • Decoded Pro$49.991 Year

Questions

Is Neptune free?
Neptune is free to download, with no in-app purchases.
Is Decoded free?
Decoded is free to download, with in-app purchases available.
Do Neptune or Decoded have ads?
Neither Neptune nor Decoded shows ads.
Which is updated more often, Neptune or Decoded?
Neptune ships an update every 2 days, and Decoded daily. Most recently, Neptune was updated on September 8, 2026 and Decoded on September 14, 2026.

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