Comparison

Shellback vs NAVADMIN Viewer

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

Head to head
About

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.

Highlights
  • 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
Features
Read full description

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.

About

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.

Highlights
  • Searchable message database
  • Offline message viewing
  • Automatic message fetching
  • Highlighted referenced publications
  • Experimental Uniform Detector
  • Customizable font options
Features
Read full description

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

Shellback3 screens
NAVADMIN Viewer4 screens

Verdict

The call

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

CostPrice · In-app purchases · Ads · Monetization

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.

ReceptionRating · Positive reviews · Number of ratings

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.

UpkeepUpdate frequency

Shellback ships an update every 11 months, NAVADMIN Viewer every 2 days. Both last shipped on November 4, 2026.

Scorecard7 real differences · 3 level
Shellback versus NAVADMIN Viewer: the parameters behind the verdict, then further details
ParameterShellbackNAVADMIN Viewer
PriceFreeFree
Rating3.2 (38 ratings)4.6 (1.1K ratings) — better
Positive reviews45.2% of reviews — better29.5% of reviews
Number of ratings381.1K — better
Update frequencyEvery 11 monthsEvery 2 days — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.0 — better18
Further details — not scored
Size89 MB15 MB
Age rating12+4+
DeveloperProgram Executive Office for Enterprise Information Systems, Sea Warrior ProgramAnson Liu

Customer experience

Shellback

All ratings38 ratings
Positive52.6%
Neutral5.3%
Negative42.1%
Written reviews42 reviews
Positive45.2%
Neutral19.0%
Negative35.7%

NAVADMIN Viewer

All ratings1,100 ratings
Positive90.8%
Neutral3.5%
Negative5.7%
Written reviews44 reviews
Positive29.5%
Neutral4.5%
Negative65.9%

User reviews

Shellback

From 38 App Store ratings

What 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 ratings

What 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 more
  • 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 more
  • 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

None

Shellback

No in-app purchases

1 purchases

NAVADMIN Viewer

Subscriptions1
  • Extended Access1 Year trial$14.991 Year

Questions

Is Shellback free?
Shellback is free to download, with no in-app purchases.
Is NAVADMIN Viewer free?
NAVADMIN Viewer is free to download, with in-app purchases available.
Which has better reviews, Shellback or NAVADMIN Viewer?
NAVADMIN Viewer is rated higher. Shellback averages 3.2 out of 5 from 38 ratings, while NAVADMIN Viewer averages 4.6 from 1.1K ratings.
Do Shellback or NAVADMIN Viewer have ads?
Neither Shellback nor NAVADMIN Viewer shows ads.
Which is updated more often, Shellback or NAVADMIN Viewer?
Shellback ships an update every 11 months, and NAVADMIN Viewer every 2 days. Most recently, Shellback was updated on November 4, 2026 and NAVADMIN Viewer on November 4, 2026.

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