Comparison

Octopus vs ShellRef

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

Head to head
About

Octopus

Learn to code in popular languages like Python, Java, Swift, and JavaScript, plus web development with HTML and CSS. Offers detailed tutorials and interactive exercises for all skill levels. Join a community of learners to advance your programming journey.

Highlights
  • Learn Python, Java, Swift, JavaScript
  • Web development with HTML and CSS
  • Detailed tutorials
  • Interactive coding exercises
  • Community collaboration
  • Courses for all levels
Features
Read full description

Start Your Adventure and Learn to Code: Embark on an enriching journey in different programming languages with our platform. Master essential languages like Python, Java, Swift, and JavaScript, and dive into web development with HTML and CSS. Our courses, tailored for all levels, aim to boost your proficiency in coding and programming. Explore Coding and Programming Essentials: Delve into the world of coding and programming through Python, Java, Swift, JavaScript, HTML, and CSS. Our detailed tutorials and hands-on exercises enhance your understanding and skills in these key languages. Master Python, Java, Swift, JavaScript, HTML, and CSS: Achieve mastery in coding and programming by exploring Python, Java, Swift, and JavaScript, alongside web technologies HTML and CSS. Our interactive exercises are designed to solidify your coding and programming capabilities. Interactive Coding and Programming Exercises: Engage in interactive coding and programming exercises across Python, Java, Swift, JavaScript, HTML, and CSS. These challenges aim to refine your skills, establishing a comprehensive foundation in coding and programming. Stay Ahead in Coding and Programming: Keep up-to-date with the latest in coding and programming. Our tutorials in Python, Java, Swift, JavaScript, HTML, and CSS ensure you remain competitive, arming you with advanced knowledge and techniques. Join Our Great Community: Become an active member of our great community. Collaborate and share insights with peers passionate about Python, Java, Swift, JavaScript, HTML, and CSS, enhancing your coding and programming journey. Advance Your Skills: Embark on your coding and programming journey, excelling in Python, Java, Swift, JavaScript, HTML, and CSS. We're dedicated to your growth, offering comprehensive resources that prepare you for the challenges ahead.

About

ShellRef

This app provides an offline reference for Bash, Zsh, and terminal editors, mimicking a retro technical manual. It's ideal for quickly looking up commands, syntax, and scripting practices without needing an internet connection. Features include search, bookmarks, and customizable display themes.

Highlights
  • Offline Bash and Zsh reference
  • Terminal editor guides (Nano, Vim, Emacs)
  • Quick command lookup
  • Searchable content
  • Customizable themes
  • Adjustable text size
  • Bookmarks
Features
Read full description

ShellRef is an offline reference for Bash, Zsh, and terminal editors, presented as a focused CRT console reference manual. It’s designed for quick lookup while you work—whether you’re writing your first shell script, checking quoting rules, reviewing Zsh behavior, or trying to remember a Vim command without opening a browser. The app includes reference sections for: • Bash fundamentals, control flow, functions, strings and arrays, file I/O, processes, and scripting practices • Zsh differences, globbing, arrays, and configuration • Common command-line tools for text processing, file operations, and system tasks • Terminal editors including Nano, Vim, and Emacs Topics are organized as short reference entries with examples, notes, warnings, and tables where they help clarify syntax and behavior. ShellRef also includes: • Offline access to the full reference library • Search across commands, topics, examples, and notes • My Quick Refs for saving frequently used entries • A CRT-inspired interface with White, Green, and Amber phosphor display modes • Optional scanlines and adjustable display glow • Reduced-effects controls for a cleaner reading experience • Adjustable text size for easier reading on iPhone and iPad ShellRef is intended for developers, sysadmins, students, and anyone who wants a readable shell reference without ads, accounts, or an internet connection.

Screenshots

Octopus4 screens
ShellRef4 screens

Verdict

The call

The clearest difference is price: Octopus at Free against ShellRef's $0.99. Octopus also leads on ratings volume (5 vs 1) and iOS requirement (13.6 vs 17.6). ShellRef's advantage is in-app purchases (none vs 4) and ads (none vs shown). On rating, update cadence 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

Octopus is free to download; ShellRef costs $0.99 up front. Octopus sells 4 in-app purchases, starting at $9.99 per month. ShellRef asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 5.0 for Octopus against 5.0 for ShellRef. That said, the two scores are not equally well evidenced: Octopus has 5 ratings behind it against 1, so its average is the more settled of the two.

UpkeepUpdate frequency

Octopus ships an update monthly, ShellRef every 3 weeks. The most recent releases landed on October 7, 2026 and October 2, 2026 respectively.

Scorecard6 real differences · 4 level
Octopus versus ShellRef: the parameters behind the verdict, then further details
ParameterOctopusShellRef
PriceFree — better$0.99
Rating5.0 (5 ratings)5.0 (1 ratings)
Positive reviews71.2% of reviews—
Number of ratings5 — better1
Update frequencyMonthlyEvery 3 weeks — better
AdsYesNo — better
In-app purchasesYesNo — better
MonetizationFree with in-app purchases — betterPaid
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS13.6 — better17.6
Further details — not scored
Size107 MB19 MB
Age rating4+4+
DeveloperAlaa CHERBIBAndrew Bacon

Customer experience

Octopus

All ratings5 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews52 reviews
Positive71.2%
Neutral9.6%
Negative19.2%

ShellRef

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

4 purchases

Octopus

Subscriptions3
  • Learn programming - 1 Month3 Days trial$9.991 Month
  • Learn programming - 3 Months3 Days trial$24.993 Months
  • Learn programming - 1 Year3 Days trial$84.991 Year
One-time1
  • Learn programming - No limits$44.99
None

ShellRef

No in-app purchases

Questions

Is Octopus free?
Octopus is free to download, with in-app purchases available.
Is ShellRef free?
ShellRef costs $0.99, with no in-app purchases.
Which has better reviews, Octopus or ShellRef?
Octopus and ShellRef are both rated 5.0 out of 5 on the App Store, from 5 and 1 ratings respectively.
Do Octopus or ShellRef have ads?
Octopus shows ads; ShellRef does not.
Which is updated more often, Octopus or ShellRef?
Octopus ships an update monthly, and ShellRef every 3 weeks. Most recently, Octopus was updated on October 7, 2026 and ShellRef on October 2, 2026.

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