The Fourth Dimension vs Crystal Flight
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
The Fourth Dimension
Explore a complex mathematical concept through an interactive 3D experience. This app uses a unique touch interface to help you visualize and understand the fourth dimension in an engaging and accessible way.
- Interactive 3D touch interface
- Explains the fourth dimension
- Accessible language for all
- 30-page interactive book
- Visual and hands-on learning
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The Fourth Dimension is a 30-page interactive book that explains a single mathematical idea in language that anyone can understand. Instead of static images or canned videos, this app employs a unique 3D touch interface that lets you literally grasp the concept of the fourth dimension with your own hands. “Not only can you blow your own mind over and over again, you can also enjoy watching your friends’ minds being blown in front of you.” — Cult of Mac “One of the coolest apps I've ever used... The Fourth Dimension is to boring learning apps what Carl Sagan's Cosmos was to staid science documentaries.” — BuzzFeed “The app is very cool, and it's unlike pretty much anything we've seen in the App Store.” — The Verge “This is one of my most favorite iOS apps ever.” — George Musser, contributing editor for Scientific American and author of The Complete Idiot's Guide to String Theory (App Store user reviews follow.) “Blew my mind. I generally don't use 'learning' apps as they're mostly gimmicks. This one, though, truly made me think. I hope this developer comes out with more outstanding apps such as this one. Bravo!” — Iceitic “Astounding. That some people care passionately enough about tesseracts to go create a fantastic app for others to understand them is incredible. The app is extremely well designed, wittily written, and executed with love. That alone is worth buying it, besides the fact that I learned what the hell a tesseract was.” — Duncan MacMichael “Fantastic! This is what someone really smart, and who really knows how to teach well, can do with a tablet. And the authors are funny, too, which is a neat bonus.” — DNY “Fantastic app. I work at a leading UK university. If only all our material was this well written and presented. Definitely worth buying and then spending a bit of time with over a day or two to get your head around the fourth dimension. Great app!” — JulesFM “Great job! This app does the best job explaining the 4th dimension. Why learn it in some boring classroom when here you can have an interactive and visual explanation.” — Aco Strklalj Over 250,000 people have blown their minds with this app.
Crystal Flight
Experience free flight within diverse crystal environments. Navigate your journey by simply tilting your iPhone or iPad to control direction.
- Free flight simulation
- Crystal environments
- Tilt-to-navigate controls
- iPhone and iPad support
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Fly freely in a variety of crystals. To navigate, simply tilt your iPhone or iPad in the direction you want to go.
Screenshots
Verdict
The clearest difference is price: Crystal Flight at Free against The Fourth Dimension's $2.99. Crystal Flight also leads on rating (5.0 vs 4.8). The Fourth Dimension's advantage is ratings volume (1.9K vs 1) and iOS requirement (12.0 vs 17.0). On update cadence, ads, in-app purchases 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
Crystal Flight is free to download; The Fourth Dimension costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Crystal Flight holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: The Fourth Dimension has 1.9K ratings behind it against 1, so its average is the more settled of the two.
The Fourth Dimension ships an update every 4 months, Crystal Flight every 5 months. The most recent releases landed on September 23, 2026 and July 5, 2026 respectively.
| Parameter | The Fourth Dimension | Crystal Flight |
|---|---|---|
| Price | $2.99 | Free — better |
| Rating | 4.8 (1.9K ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 94.2% of reviews | — |
| Number of ratings | 1.9K — better | 1 |
| Update frequency | Every 4 months — better | Every 5 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Mac |
| Requires iOS | 12.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 5 MB | 4 MB |
| Age rating | 4+ | 4+ |
| Developer | Lunar Skydiving LLC | Jeff Weeks |
Customer experience
The Fourth Dimension
Crystal Flight
In-app purchases
The Fourth Dimension
No in-app purchases
Crystal Flight
No in-app purchases
Questions
Is The Fourth Dimension free?
Is Crystal Flight free?
Which has better reviews, The Fourth Dimension or Crystal Flight?
Do The Fourth Dimension or Crystal Flight have ads?
Which is updated more often, The Fourth Dimension or Crystal Flight?
Other comparisons
