Comparison

Gravity 6D vs DEC Opcodes

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

Head to head
About

Gravity 6D

Explore advanced physics with this application that allows for the simulation of up to six-dimensional gravity. Customize simulation parameters, adjust speed and visuals, and save your creations for later review.

Highlights
  • 6D mass particle simulations
  • Customizable simulation setup
  • Adjustable simulation speed
  • Visual preference settings
  • Save simulations
Features
Read full description

See the new possibilities of gravity simulations with Gravity 6D! With this app, you can simulate up to 6 dimensional gravity simulations. Main features: • Simulate up to 6 dimensional mass particle simulations • Setup your simulation with various settings • Adjust simulation speed and visual preferences • Save your simulations for later

About

DEC Opcodes

Explore the instruction sets of legendary DEC computers like the PDP and VAX. This app provides detailed information on each instruction, historical context, and interactive lessons. Discover the machines that shaped modern computing.

Highlights
  • Instruction set reference
  • Historical context and photos
  • System specifications
  • Interactive assembly lessons
  • Search and filtering
  • Customizable themes
  • Simple assembler
Features
Read full description

Dec Opcodes – DEC Architecture Reference Before the microprocessor, there was DEC. The minicomputers built by Digital Equipment Corporation didn't just advance computing - they defined it. Unix was born on a PDP-7. Spacewar! ran on a PDP-1. The field of Artificial Intelligence was born on the PDP-10. The VAX powered universities and research labs worldwide for a generation. DecOpcodes puts the complete instruction sets of these legendary machines in your pocket. Five iconic architectures covered: PDP-1 (1960) · PDP-8 (1965) · PDP-10 (1966) · PDP-11 (1970) · VAX (1977) For every instruction:  • Full description of what the instruction does  • Octal and hex encoding  • Flags affected  • Addressing modes, word count, and cycle counts  • Assembly code examples and implementation notes But there is a lot more than just dry opcodes:  • Complete system specifications and register architecture  • Historical context and cultural impact  • Archival photographs - front panels, system cabinets, and more  • Notable installations and the systems they powered  • Architecture variants and successors • Interactive lessons on assembly language and console operations (ideal if you have an PiDP emulator) Built for exploration:  • Search across all systems instantly • A simple assembler for PDP-1, -8 and -11 code • Filter by instruction category  • Sort alphabetically or by category • Favorite instructions for quick reference Beautifully designed:  • System-specific accent colours  • Five themes including Terminal green and Blinkenlights orange  • Full Dark Mode support From the 18-bit simplicity of the PDP-1 to the 32-bit sophistication of the VAX, DecOpcodes is a fascinating and interactive journey through the machines that made modern computing possible. All features are free and unlocked. If you like the app you can always leave a nice review or tip the developer!

Screenshots

Gravity 6D4 screens
DEC Opcodes4 screens

Verdict

The call

The clearest difference is price: DEC Opcodes at Free against Gravity 6D's $1.99. DEC Opcodes also leads on update cadence (every 8 days vs every 16 months) and ratings volume (3 vs 1). Gravity 6D's advantage is in-app purchases (none vs 1) and iOS requirement (12.0 vs 18.0). On rating, 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

DEC Opcodes is free to download; Gravity 6D costs $1.99 up front. DEC Opcodes sells 1 one-off in-app purchase. Gravity 6D 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 Gravity 6D against 5.0 for DEC Opcodes. Both are backed by a comparable volume of ratings — 1 and 3 respectively.

UpkeepUpdate frequency

Gravity 6D ships an update every 16 months, DEC Opcodes every 8 days. The most recent releases landed on September 26, 2026 and October 7, 2026 respectively.

Scorecard6 real differences · 3 level
Gravity 6D versus DEC Opcodes: the parameters behind the verdict, then further details
ParameterGravity 6DDEC Opcodes
Price$1.99Free — better
Rating5.0 (1 ratings)5.0 (3 ratings)
Number of ratings13 — better
Update frequencyEvery 16 monthsEvery 8 days — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaidFree — better
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS12.0 — better18.0
Further details — not scored
Size49 MB42 MB
Age rating4+4+
DeveloperCreetah Ltd.John Kennedy

Customer experience

Gravity 6D

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

DEC Opcodes

All ratings3 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Gravity 6D

No in-app purchases

1 purchases

DEC Opcodes

One-time1
  • Buy Me a Coffee$0.99

Questions

Is Gravity 6D free?
Gravity 6D costs $1.99, with no in-app purchases.
Is DEC Opcodes free?
DEC Opcodes is free to download, with in-app purchases available.
Which has better reviews, Gravity 6D or DEC Opcodes?
Gravity 6D and DEC Opcodes are both rated 5.0 out of 5 on the App Store, from 1 and 3 ratings respectively.
Do Gravity 6D or DEC Opcodes have ads?
Neither Gravity 6D nor DEC Opcodes shows ads.
Which is updated more often, Gravity 6D or DEC Opcodes?
Gravity 6D ships an update every 16 months, and DEC Opcodes every 8 days. Most recently, Gravity 6D was updated on September 26, 2026 and DEC Opcodes on October 7, 2026.

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