Comparison

a vs O

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

Head to head
About

a

Run a full Unix-like terminal environment on your iOS device. Execute a wide range of commands, edit files, and even program using included interpreters and compilers. Supports multitasking and integration with Shortcuts.

Highlights
  • Local Unix terminal emulator
  • SSH client
  • File transfer (scp, curl)
  • Text editing (vim, ed)
  • Scripting languages (Python, Lua, Perl, JS)
  • C/C++ compiler
  • TeX distribution
Features
Read full description

a-Shell is a complete local terminal emulator, allowing to run most Unix commands on your iOS device. You can transfer files using scp and curl, edit them with vim and ed, process them using grep, awk and sed. You can work with git repositories using lg2.  Most commands are compiled for iOS native Arm64 format, making them fast and well integrated with the BSD Unix that powers iOS/iPadOS. a-Shell includes Python, Lua, Perl, JavaScript, C, C++ for programming and TeX (texlive 2025, with Tikz and LuaTeX) for text processing. There are also multiple network utilities: nslookup, ping, whois, ifconfig... Type help for help, help -l to get the full list of commands. a-Shell can be controlled from Shortcuts: run commands in order, process files in a-Shell, get the results as text or files, transfer files to other apps... a-shell uses iOS 13+ “multiple windows” ability, so you can run multiple shells at the same time, with different commands, in different directories. You can edit a file in one window with vim and process it in the other with python. Compile your C or C++ programs to webAssembly using clang or clang++, and execute the resulting binary. A complete webAssembly SDK is included (WASI-libc). a-Shell is the complete version. If you need a smaller app, and you don't need a C compiler, a TeX engine, or numpy and matplotlib, there is a-Shell mini.

About

O

Monitor your home remotely with real-time video surveillance. Access cloud storage, receive alarm notifications, and communicate via two-way audio. Capture photos and videos for convenient home management.

Highlights
  • Real-time video monitoring
  • Cloud storage playback
  • Alarm push notifications
  • Two-way voice intercom
  • Photo and video capture
  • Simple operation and design
Features
Read full description

O-KAM Pro, feel home anytime, anywhere. A remote video surveillance software used with the camera can help you check the dynamics of your home at any time after adding the camera. With real-time video, cloud storage playback, alarm push, two-way voice intercom, as well as photo and video and other functions. APP has simple operation and simple design, which can help you manage and use it more conveniently.

Screenshots

a4 screens
O4 screens

Verdict

The call

The clearest difference is in-app purchases: a at none against O's 25. a also leads on ads (none vs shown) and review sentiment (78% vs 63%). O's advantage is ratings volume (8.6K vs 553) and chart position (#6 vs #21). On price, 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

Both are free to download. O sells 23 one-off in-app purchases. a asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.6 for a against 4.5 for O. That said, the two scores are not equally well evidenced: O has 8.6K ratings behind it against 553, so its average is the more settled of the two. Written reviews are what separate them: 78% of a's written reviews are positive against 63% of O's.

UpkeepUpdate frequency

a ships an update monthly, O fortnightly. The most recent releases landed on October 17, 2026 and October 19, 2026 respectively.

Scorecard6 real differences · 5 level
a versus O: the parameters behind the verdict, then further details
ParameteraO
PriceFreeFree
Rating4.6 (553 ratings) — better4.5 (8.6K ratings)
Positive reviews78.3% of reviews — better62.9% of reviews
Number of ratings5538.6K — better
Update frequencyMonthlyFortnightly — better
AdsNo — betterYes
In-app purchasesNo — betterYes
MonetizationPaidFree with in-app purchases — better
Best chart rank#21#6 — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS14.013.0 — better
Further details — not scored
Size1.9 GB366 MB
Age rating17+17+
DeveloperNicolas HolzschuchShenzhen VeePai IoT Intelligent Technology LLC

Customer experience

a

All ratings553 ratings
Positive88.1%
Neutral4.5%
Negative7.4%
Written reviews387 reviews
Positive78.3%
Neutral9.6%
Negative12.1%

O

All ratings8,584 ratings
Positive88.3%
Neutral2.7%
Negative8.9%
Written reviews2,111 reviews
Positive62.9%
Neutral6.3%
Negative30.8%

User reviews

a

From 553 App Store ratings

What we love

  • 🚀 Powerful terminal with Linux commands
  • 👍 Useful for programming and development
  • 🔒 Secure and reliable
  • 💡 Impressive capabilities for an iOS app
  • 👍 Helpful documentation and developer support

Room to improve

  • 🐛 Occasional crashes and bugs
  • 🔍 Limited customization options
  • 🔍 Missing some basic terminal features
  • 🔍 Compatibility issues with certain packages

O

From 8.6K App Store ratings

What we love

  • 🚀 Convenient
  • 🚀 Easy to use
  • 🚀 Great picture quality
  • 🚀 Excellent value
  • 🚀 Reliable

Room to improve

  • 🐛 Connectivity issues
  • 🐛 Unreliable motion detection
  • 🔋 Battery life concerns
  • 🔍 Difficult to navigate app
  • 💸 Expensive subscription

Bugs and requests

a

Reported bugs

3 issues
  • Toolbar buttons not accessible in portrait mode on some devices
  • Pasting from clipboard can insert unexpected characters
  • Sourcing certain script files causes crashes

Requested features

5 requests
  • Add support for package managers like Homebrew or APT
  • Implement more advanced shell features like job control and better tab completion
  • Integrate Git for version control
  • Allow installing additional packages and libraries
  • Improve clipboard and file management integration

O

Reported bugs

3 issues
  • Frequent app crashes
  • Inability to view recorded footage
  • Inconsistent camera performance after updates

Requested features

5 requests
  • Easier cloud storage management
  • Improved motion detection sensitivity
  • More customization options
  • Ability to disable microphone/speakers
  • Smoother app performance

In-app purchases

None

a

No in-app purchases

23 purchases

O

One-time23
  • monthly card-7(SA tryout)$0.99
  • monthly card-7(tryout)$0.99
  • monthly card-7(EU tryout)$0.99
Show 20 more
  • monthly card-7(JP tryout)$0.99
  • monthly card-7(AE tryout)$0.99
  • monthly card$1.99
  • monthly card2 variants$2.99
  • monthly card(JP)-7$2.99
  • monthly card- 7$3.99
  • monthly card- 30$4.99
  • monthly card2 variants$5.99
  • monthly card(JP)- 30$5.99
  • monthly card(SA)- 30$5.99
  • half year card$6.99
  • monthly card(AE)-30$7.99
  • yearly card$12.99
  • half year card$14.99
  • yearly card$24.99
  • half year card -7$28.99
  • half year card$31.99
  • yearly card$49.99
  • yearly card - 7$49.99
  • half year card -30$74.99

Questions

Is a free?
a is free to download, with no in-app purchases.
Is O free?
O is free to download, with in-app purchases available.
Which has better reviews, a or O?
a is rated higher. a averages 4.6 out of 5 from 553 ratings, while O averages 4.5 from 8.6K ratings.
Do a or O have ads?
O shows ads; a does not.
Which is updated more often, a or O?
a ships an update monthly, and O fortnightly. Most recently, a was updated on October 17, 2026 and O on October 19, 2026.
Which is more popular, a or O?
a currently peaks at #21 in the App Store charts, and O at #6. Chart position reflects recent download velocity rather than total install base.

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