Shellback vs NAVADMIN Viewer
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Shellback
This app provides US Naval Surface Force personnel with offline access to essential information. It includes manuals and resources for administration, medical, operations, personnel management, safety, and navigation rules. Content is updated annually for relevance.
- Offline access to SURFOR information
- Admin/Training manuals
- Medical readiness resources
- Operations and navigation training
- Personnel management documents
- Safety information and lessons learned
- Rules of the Road quiz
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What is the Shellback app? Shellback, formerly known as eDivo, is a free mobile app developed to support US Naval Surface Force (SURFOR) personnel in an easy-to-access offline environment. What is a Shellback? In naval tradition, a Shellback is a nickname for a Sailor who has crossed the Equator and thus transitioned from a novice Sailor, or Pollywog, to an experienced Sailor. Why do I need Shellback? Shellback provides Sailors the ability to download key SURFOR information on their own portable devices and access it while underway without the need for an internet connection. Shellback provides the most relevant and current information to SURFOR Sailors in one location. Content is scheduled for annual updates. What type of info can I find in Shellback? The information in Shellback is separated into several main categories: -Admin/Training: Contains the Correspondence Manual and the SURFOR Training and Readiness Manual. -Medical: Includes the Manual of the Medical Department, information on medical and physical readiness, mental health, Medical Evaluation Board procedures, the Disability Evaluation System, family member readiness, and more. -Operations: Includes information and training on bridge management, navigation basics, watch team tools, crew endurance, operating procedures for air-capable ships, Air Certification for Naval Surface Force Ships, and manuals for amphibs, maintenance, and other general ship operation resources. -Personnel Management: Provides documents on Navy personnel policy and administration. Also includes legal handbooks and manuals, resources for Surface Warfare Officers, and a variety of general personnel management resources. -Safety: Provides documents related to lessons learned, mishap reporting, notices, safety-related awards, and general safety resources. -Rules of the Road: This quiz tests a Sailor’s knowledge of maritime navigation rules.
NAVADMIN Viewer
Access and search official Navy and Marine Corps administrative messages on your mobile device. View messages offline, find referenced publications easily, and utilize features like Spotlight Search and Siri Shortcuts. An experimental tool can even identify military ribbons and medals.
- Searchable message database
- Offline message viewing
- Automatic message fetching
- Highlighted referenced publications
- Experimental Uniform Detector
- Customizable font options
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Read and search Navy and Marine Corps messages. Get notified when new messages are available. NAVADMIN, ALNAV, MARADMIN, and ALMAR messages are stored locally for offline viewing and search. Search across all messages without opening individual files. NAVADMIN Viewer automatically notifies you about the latest messages as they are released. Messages are stored locally and available for offline viewing. Referenced publications within a message are automatically highlighted for quick viewing and search. Star messages for quick access. Message statistics show recent stars and views. Choose from a variety of reading fonts in Settings. Older messages may require a short delay to view. Optional Extended Access lets you view all messages without waiting. Additional features: - Messages in Spotlight Search - Siri Shortcuts - Home Screen Quick Actions - Handoff NAVADMINs and ALNAVs are Navy administrative messages. MARADMINs and ALMARs are Marine Corps administrative messages. This app comes with No Warranty of Accuracy. All data is provided as is and the user is responsible for verifying any data with offical sources. Use of this app is subject to the Terms of Use (EULA) at https://www.apple.com/legal/internet-services/itunes/dev/stdeula/.
Screenshots
Verdict
The clearest difference is rating: NAVADMIN Viewer at 4.6 against Shellback's 3.2. NAVADMIN Viewer also leads on update cadence (every 2 days vs every 11 months) and ratings volume (1.1K vs 38). Shellback's advantage is in-app purchases (none vs 1) and review sentiment (45% vs 30%). 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. NAVADMIN Viewer sells 1 in-app purchase, starting at $14.99 per year. Shellback asks for nothing beyond the download.
NAVADMIN Viewer holds the better App Store score, 4.6 against 3.2. That said, the two scores are not equally well evidenced: NAVADMIN Viewer has 1.1K ratings behind it against 38, so its average is the more settled of the two. Written reviews complicate that: 45% of Shellback's written reviews are positive against 30% of NAVADMIN Viewer's, so the app with the better star average is not the one people write more warmly about.
Shellback ships an update every 11 months, NAVADMIN Viewer every 2 days. Both last shipped on November 4, 2026.
| Parameter | Shellback | NAVADMIN Viewer |
|---|---|---|
| Price | Free | Free |
| Rating | 3.2 (38 ratings) | 4.6 (1.1K ratings) — better |
| Positive reviews | 45.2% of reviews — better | 29.5% of reviews |
| Number of ratings | 38 | 1.1K — better |
| Update frequency | Every 11 months | Every 2 days — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.0 — better | 18 |
| Further details — not scored | ||
| Size | 89 MB | 15 MB |
| Age rating | 12+ | 4+ |
| Developer | Program Executive Office for Enterprise Information Systems, Sea Warrior Program | Anson Liu |
Customer experience
Shellback
NAVADMIN Viewer
User reviews
Shellback
From 38 App Store ratingsWhat we love
- 👍 Great all-in-one tool
- 👍 Useful for all ranks
- 👍 Good reference tool
- 👍 Handy for quick lookups
- 👍 Contains essential references
Room to improve
- outdated information
- ❓ ROR quiz lacks correct answers
- ❓ Uniform regulations not loading
- ❓ App crashes on feedback
- ❓ Outdated PFA instruction
NAVADMIN Viewer
From 1.1K App Store ratingsWhat we love
- 👍 Convenient and easy to use
- 🚀 Efficient for quick reference
- 💡 Useful for teaching young sailors
Room to improve
- 💰 Paywall for accessing older messages
- 🔓 Free alternative available on website
- 🐛 App not updating with new messages
Bugs and requests
Shellback
Reported bugs
8 issues- App crashes when trying to enter feedback
- Uniform regulations documents do not load
- App crashes on iOS system update
- App won't open after update
- App won't download completely
Show 3 moreShow fewer
- Female uniform regulations don't open
- Sections highlight but do not open
- App won't download on new phone
Requested features
25 requests- Add more content to the app
- Provide correct answers for ROR quiz
- Show COLREGs rule for ROR questions
- Add underway mode to download all refs
- Include aviation community instructions
Show 20 moreShow fewer
- Add Navy Correspondence Manual
- Include MILPERSMAN
- Add JJDIDTIEBUCKLE
- Improve CDB gouge
- Add reminder tool to calendar
- Add hyperlinks to current instructions with offline option
- Include full versions of instructions and training
- Add more check list instructions
- Add a more general app version
- Add more instructions to current app
- Add Correspondence Manual
- Add MILPERSMAN
- Add JJDIDTIEBUCKLE
- Improve CDB gouge
- Add reminder tool to calendar
- Add hyperlinks to current instructions with offline option
- Include full versions of instructions and training
- Add more check list instructions
- Add a more general app version
- Add more instructions to current app
NAVADMIN Viewer
Reported bugs
2 issues- App crashing or shutting down
- Compatibility issues with device updates
Requested features
3 requests- Add widgets for quick access
- Include more Navy resources (ALNAV, FORCM, etc.)
- Improve notification system
In-app purchases
Shellback
No in-app purchases
NAVADMIN Viewer
- Extended Access1 Year trial$14.991 Year







