Comparison

Jupiter ACE vs learnFORTH

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

Head to head
About

Jupiter ACE

Explore the history of computing by learning the Forth programming language on a simulated 1982 home computer. This educational tool provides an authentic experience for aspiring programmers interested in retro technology.

Highlights
  • Forth programming language simulation
  • 1982 home computer emulation
  • Educational retro computing experience
  • Freely available source code
  • iPad compatible
Features
Read full description

Go back in time and learn to program Forth with this Jupiter ACE on your iPad. The Jupiter ACE was a home computer released back in 1982. While all other home computers at the time used BASIC as the built in programming language, the Jupiter ACE used Forth. This emulator is built with freely available documents and source code. Project files are available on github. Jupiter ACE is trademark of Andrews UK Ltd.

About

learnFORTH

Learn the compact, stack-based Forth programming language through structured daily lessons and interactive exercises. Explore its history and applications in embedded systems and retro computing.

Highlights
  • 90 structured daily lessons
  • Interactive REPL with syntax highlighting
  • Hands-on exercises with hints
  • Progress tracking and daily streaks
  • Reverse Polish Notation primer
  • Historical notes on Forth dialects
Features
Read full description

It's time to learn Forth, the compact stack-based language that powered navigation computers, embedded systems, and a generation of hands-on hackers - and still runs the boot firmware on some retro Sun and Apple hardware. If you ever saw a Jupiter ACE home computer, now is your change to learn about what made it special. This app teaches you to think in words and stacks with 90 short, structured daily lessons, a live REPL you can experiment in right on your phone or iPad, and hands-on exercises with hints (not answers) so you actually learn the ideas. WHAT'S INSIDE • 90 guided lessons across 7 topics: the data stack, words & variables, control flow, loops & recursion, advanced words, data structures, and advanced topics. • A built-in REPL with syntax highlighting so you can type real FORTH and see the stack respond immediately. • Exercises for every lesson, graded on output, with an optional hint if you get stuck. • Daily streaks and per-category progress tracking to keep you moving. You'll learn, promise! • A plain-English primer on Reverse Polish Notation and stack manipulation (DUP, DROP, SWAP, OVER, ROT) for complete beginners. • Historical notes on FORTH's dialects - fig-FORTH, Forth-79, Forth-83, ANS Forth - and which one this app's interpreter follows. • A tip-of-the-hat to the Jupiter ACE, the British home computer from the 1980s that was based on Forth. • A recommended reading list of classic FORTH books, including Starting FORTH and Thinking Forth by Leo Brodie. • Light, dark, and automatic themes. No prior programming experience required. If you've ever wondered how a language with almost no syntax can still get real work done, learnFORTH will show you, one word at a time. Note: This app is free, with all features always available. If you enjoy it, please use the tip feature to thank the author and encourage future development.

Screenshots

Jupiter ACE3 screens
learnFORTH4 screens

Verdict

The call

The clearest difference is rating: learnFORTH at 5.0 against Jupiter ACE's 4.0. learnFORTH also leads on review sentiment (100% vs 67%) and update cadence (every 5 days vs every 63 months). Jupiter ACE's advantage is iOS requirement (15.0 vs 18.6). On price, ratings volume, ads and in-app purchases 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. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

learnFORTH holds the better App Store score, 5.0 against 4.0. Both are backed by a comparable volume of ratings — 8 and 3 respectively. Written reviews point the same way: 67% of Jupiter ACE's written reviews are positive against 100% of learnFORTH's.

UpkeepUpdate frequency

Jupiter ACE ships an update every 63 months, learnFORTH every 5 days. The most recent releases landed on October 2, 2026 and September 21, 2026 respectively.

Scorecard4 real differences · 6 level
Jupiter ACE versus learnFORTH: the parameters behind the verdict, then further details
ParameterJupiter ACElearnFORTH
PriceFreeFree
Rating4.0 (8 ratings)5.0 (3 ratings) — better
Positive reviews66.7% of reviews100.0% of reviews — better
Number of ratings8 — better3
Update frequencyEvery 63 monthsEvery 5 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.0 — better18.6
Further details — not scored
Size35 MB2 MB
Age rating4+4+
DeveloperMemention Holding ABJohn Kennedy

Customer experience

Jupiter ACE

All ratings8 ratings
Positive75.0%
Neutral12.5%
Negative12.5%
Written reviews9 reviews
Positive66.7%
Neutral11.1%
Negative22.2%

learnFORTH

All ratings3 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Jupiter ACE

No in-app purchases

None

learnFORTH

No in-app purchases

Questions

Is Jupiter ACE free?
Jupiter ACE is free to download, with no in-app purchases.
Is learnFORTH free?
learnFORTH is free to download, with no in-app purchases.
Which has better reviews, Jupiter ACE or learnFORTH?
learnFORTH is rated higher. Jupiter ACE averages 4.0 out of 5 from 8 ratings, while learnFORTH averages 5.0 from 3 ratings.
Do Jupiter ACE or learnFORTH have ads?
Neither Jupiter ACE nor learnFORTH shows ads.
Which is updated more often, Jupiter ACE or learnFORTH?
Jupiter ACE ships an update every 63 months, and learnFORTH every 5 days. Most recently, Jupiter ACE was updated on October 2, 2026 and learnFORTH on September 21, 2026.

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