# ASTB Prep vs CBDR

The clearest difference is in-app purchases: CBDR at none against ASTB Prep's 2. CBDR also leads on update cadence (weekly vs fortnightly). ASTB Prep's advantage is ratings volume (450 vs 5). On price, rating, ads and device support there is nothing between them.

Both are free to download. ASTB Prep sells 2 one-off in-app purchases. CBDR asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 4.9 for ASTB Prep against 5.0 for CBDR. That said, the two scores are not equally well evidenced: ASTB Prep has 450 ratings behind it against 5, so its average is the more settled of the two.

ASTB Prep ships an update fortnightly, CBDR weekly. The most recent releases landed on November 3, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | ASTB Prep | CBDR |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.9 (450 ratings)](https://appshunter.io/ios/app/astb-prep/id1549216388/reviews) | **[5.0 (5 ratings)](https://appshunter.io/ios/app/cbdr/id6792199258/reviews)** |
| Number of ratings | **450** | 5 |
| Positive reviews | 93.6% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Fortnightly | **Weekly** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 816 MB | 80 MB |
| Requires iOS | 17.0 | 17.0 |
| Devices | **iPhone, iPad, Mac** | iPhone, iPad |
| Age rating | 9+ | 4+ |
| Developer | [Alex Hastings](https://appshunter.io/developer/1549216390) | [Sean Bowman](https://appshunter.io/developer/6792199260) |

## What reviewers say

### ASTB Prep

[App page](https://appshunter.io/ios/app/astb-prep/id1549216388)

Prepare for military aviation exams with comprehensive lessons, practice tests, and realistic simulators. Track your progress and study offline for the ASTB-E and OAR tests.

**Highlights:** Comprehensive lessons for ASTB-E and OAR, 1200+ sample test questions with explanations, Adaptive practice tests, Realistic PBM simulators (DLT, UAV, TI, RC), Offline content access, Progress tracking, Controller support for simulators

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Joystick Functionality | Free | one-time |
| Full Access | $39.99 | one-time |

**What reviewers like**

- 🚀 Great tool for ASTB prep
- 👍 Comprehensive study materials
- 🚀 Helpful simulators for PBM
- 🚀 Improved test scores
- 👍 Detailed lessons and practice tests

**What reviewers complain about**

- 🐛 Some math/physics questions have incorrect answers
- 🐛 UAV simulator not fully accurate to real test
- 🐛 Stick and throttle simulator needs improvement

**Reported bugs**

- Mechanical comprehension test has 30 questions, not 20
- Terrain identification section has occasional screen color issues

**Requested features**

- Option to disable timer for terrain identification
- Ability to configure duration of correct answer display
- Add audio for UAV portion to simulate real test experience
- Include emergency scenario training for UAV


### CBDR

[App page](https://appshunter.io/ios/app/cbdr/id6792199258)

This app trains junior deck officers and watchstanders in essential radar watch skills, including contact evaluation, COLREGS classification, and generating contact reports. It features a live radar scope, generated scenarios for various navigation situations, and drills for recognition and maneuvering.

**Highlights:** Live radar scope with vectors and trails, Generated navigation scenarios, COLREGS classification, Contact report scoring, Maneuvering board drills, Recognition drills, USCG Rules of the Road test bank, Offline group testing

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is ASTB Prep free?

ASTB Prep is free to download, with in-app purchases available.

### Is CBDR free?

CBDR is free to download, with no in-app purchases.

### Which has better reviews, ASTB Prep or CBDR?

CBDR is rated higher. ASTB Prep averages 4.9 out of 5 from 450 ratings, while CBDR averages 5.0 from 5 ratings.

### Do ASTB Prep or CBDR have ads?

Neither ASTB Prep nor CBDR shows ads.

### Which is updated more often, ASTB Prep or CBDR?

ASTB Prep ships an update fortnightly, and CBDR weekly. Most recently, ASTB Prep was updated on November 3, 2026 and CBDR on October 31, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*